As these are rumors, I don't believe the X-Wing will be released in 2012. Here's why:
1. While the X-Wing fighter that is currently out (6212) has been on the shelf for longer than most LEGO Star Wars sets, it's a set that continues to sell exceptionally well. Most LBR stores continue to get shipments of this product, even though it is sold out on LEGO.com.
2. Never once in the history of LEGO Star Wars has a redesigned set been released while an earlier version of the product is still being manufactured. It would be a horrible move by LEGO to manufacture two of the exact same ship (even if there are slight modifications or changes to the minifigures).
Rumors of the Y-Wing would make more sense. We haven't had a Y-Wing from the Original Trilogy since 2006-7ish and the Clone Wars version was discontinued earlier this year.