If the TV deal is right, I think BYU needs to join the Big East. Here are a few reasons (not all the reasons):
1) A BCS conference invite isn't coming along any time soon...and if it does then BYU can bail on the Big East at that point.
2) Being the big fish in the little pond is sometimes advantageous. In this case, depending on the TV deal, being in the Big East could provide all the benefits of Independence--without all the risks.
3) If UCF can get the #15 ranking with a really crappy schedule (and one guaranteed loss to Ohio State) then this bodes well for BYU against a better schedule in the Big East.
4) Conference championship to play for... I love having the conference championship race to look forward to...
5) Play games all across the country and stretch the recruiting base. BYU fans attend away games like crazy. I live close to a couple of the new 'Big East' teams and I'd make the trip to see the Cougs play.
...what it all boils down to is the fact that BYU just has to win. BYU couldn't have asked for two worst outcomes to start the first two years of independence. Sure, BYU had a 10 win season last year--but getting destroyed in all of the marquee games didn't help the cause... This year the motto needs to be: Just win, baby.