Cable or network?
Once the conclusion is reached that the story must be adapted to television, the next question is whether a deal should be pursued with one of the big, universally-available TV networks in the USA (such as ABC or NBC), or with one of the smaller, but usually more flexible, cable networks. If we assume that HBO would not be interested because of their commitment to Game of Thrones, that leaves stations such as Starz, AMC and Showtime as possible contenders. The smaller cable stations, like SyFy, would almost certainly lack the resources to tackle the project with adequate funding.
This question is important for practical reasons. Most notably, the networks usually have longer seasons than cable. If this was the sole issue, in fact, it would be a no-brainer to go with a network. With 20-24 episodes per season, it would be easy to cover two or maybe even three books a season, easily enough to tell the whole story. This would even include the duller moments later on, though I would still argue in favour of condensing events in the third quarter of the series to maybe half the length of narrative they currently span, if not less, to improve pacing.
Of course, there are drawbacks to being on a network. The biggest are money and how much of a chance the series would be given to prove itself before cancellation. Networks are notoriously trigger-happy on cancelling shows early, even when prior evidence shows this to be a self-defeating practice. For example, Seinfeld was almost cancelled at birth due to low ratings, but given another chance and went on to become one of the biggest American TV shows of all time. This tendency increases exponentially the more money is poured into a project. The head of ABC was fired for profligacy after greenlighting Lost's pilot with an astonishing $15 million budget, even though it rewarded that investment by going on to become the biggest thing on TV for a couple of years. A Wheel of Time TV show would require more than the standard $2 million-per-episode budget common to network genre projects (Game of Thrones's budget is more like $6 million per episode, for comparison's sake), which would make it much more likely to be dropped should ratings not match expectations almost immediately.
That said, networks have become more willing to give shows a chance in the last few years. Fox gave both Dollhouse and Terminator: The Sarah Connor Chronicles two seasons each to prove themselves before cancelling them, apparently learning from the short-termism that led to the premature cancellation of Firefly several years earlier (later shown to be a mistake after impressive DVD box set sales). They've also shown a willingness to invest more money if the show is a success: Lost's budget (after the generously-budgeted pilot) reached $5 million per episode by the final season, whilst Heroes enjoyed $4 million per episode until its final season, when the budget was slashed in the face of sharply dropping ratings. Still, the greater risk of immediate cancellation makes the networks an uneasy choice to pursue.
On cable, the issues are different. First off, the success of Thrones on HBO means that the other big cable networks will almost certainly be receptive to having a fantasy TV project of their own, especially one where the books are (or were, before Game of Thrones started on TV, anyway) even more popular with an even larger fanbase and an even greater name awareness. Also, whilst the other cable companies don't have HBO's impressive financial resources, they can usually muster up larger budgets than most of the standard networks. Shows like The Tudors (on Showtime), The Walking Dead (on AMC) and Spartacus (on Starz) enjoy significantly more resources than most network shows, whilst not quite being in HBO's league.
The trade-off for more money is shorter seasons. 8-12 episodes per season is normal on a cable network, and 16 episodes (for Season 3 of The Walking Dead or Season 4 of Oz) is the absolute maximum, usually only possible after the show has been a proven success. This is a major limitation in adapting The Wheel of Time for a cable network. If we assume 12 episodes (probably the maximum realistic figure for the first season, at least), that means either hoping the series goes for 10+ seasons (highly implausible) or condensing the story down, which, if not handled right, could takes us back to the movie problem of the project not being worthwhile in the first place.
Length of the seasons
So the question becomes, how much time is necessary to tell the Wheel of Time story on TV? How many episodes should each book cover? Looking at Game of Thrones on HBO, the 800-page first novel had to have a noticeable number of minor plots (mostly flashbacks) and characters shaved off to fit into ten episodes. If for Wheel we accept that we have to cover a minimum of two books per season (meaning a seven season show) and, on cable, only twelve episodes per season will be available, that gives us the prospect of fitting each Wheel of Time novel into just six hour-long episodes.
This initially looks dubious, until several things are factored in. First off, six hours is still twice the absolute maximum length of a potential Eye of the World movie, and more likely closer to three times. So it's still the better option from a time perspective. In addition, Robert Jordan's natural verbosity and tendency towards detailed descriptions means that fitting 800 pages into six hours is actually more straightforward than it appears. The Eye of the World is marginally longer than A Game of Thrones (306,000 words to 298,000) but a plot summary of the former is much more straightforward. The plot is more linear with considerably fewer characters overall, and certainly far fewer 'main' characters (at least at this point). Unlike Thrones, the narrative doesn't need to cover three distinct and major storylines (and several smaller ones) unfolding thousands of miles apart. There is a section mid-book where the characters divide into three groups and reconvene a few chapters later on, but this is still less problematic than the issues faced by Thrones in its first season. The Great Hunt, which would form the remainder of a first season, would be slightly more challenging (due to the characters being apart for a much larger part of the book), especially from a budgetary standpoint given the action that takes place at sea, but time-wise it could fit into six episodes even more easily than the first book (it's somewhat shorter, to start with).
In short, although it would still be something of a squeeze, it should still be possible to fit The Eye of the World and The Great Hunt into twelve episodes. Given the superior budgets available on cable, and the greater likelihood of the show at least making it to a full season before cancellation is a danger, this leads me to conclude that pursuing an adaptation on one of the bigger US cable channels is the logical way to proceed, despite the tighter time constraints.
With HBO unlikely to want to have a show competing with Thrones on their own network, one of these three is the most logical choice to make a Wheel of Time series.
Next time (and hopefully not a year down the line!): shaping the entire story into a TV series and how future seasons would face the challenge of adapting both the longer books in the series and also handling the 'slower' books later on.