It's getting downright silly, but Digitimes is now claiming iPad 2 will indeed have a 2048x1536 based on " upstream component makers". This follows Daring Fireball saying oh-no-it-wouldn't, MacRumors finding evidence it just might, Kevin Rose saying iPad 2 would be higher-res but not Retina Display and Engadget confirming the same (which TiPb found problematic for compatibility reasons), and 9to5Mac pointing to iPad 2 staying at the current 1024x768.
Apple almost certainly has a 2048x1536 Retina Display iPad in the lab, perhaps they're even testing it for production runs. If they can deliver it along with 1 or 2 cameras, an Apple A5 chipset, and much more RAM and keep the same $499 entry level price point, perhaps we'll see it this year. If they can't then maybe we'll get the "backup" iPad 2 with the same 1024x768 display and Retina will be scheduled for iPad 3 in 2012. (They may even be testing a 1.25x and/or 1.5x "hi-res" display as well to see how current apps perform at <a href=""http://www.imore.com/2011/01/19/problem-2x-ipad-2-retina-display/">shrunken or stretched sizes, who know?)
Either way we'll probably keep hearing conflicting rumors until Apple calls an event and announces iPad 2.