Exactly. Reading this forum it's almost like people have no idea how secure Apple's market position is in tablets. If Apple doesn't come out with a high resolution screen this year, most (if not all) the people carping about ipad 2's screen will wait for the 3 next year. The logic people are offering for why an HD/Pro model will come out in 2011 doesn't conform to Apple's MO nor has any particularly significant evidence been brought forth to suggest that Apple is in danger of losing its market position in tablets. If anything, the less-than-enthusiastic reception several competing tablets (Transformer, Xoom, Playbook, Touchpad) really seems to limit the possibility of such an imperative.
Aside from that, I doubt Apple is going to want to sacrifice on speed, battery life, or thermal envelope (to keep weight/thickness down), and that means they really need at a die shrink and most likely Cortex-A15 (and probably PVR6), which isn't coming out before 2012. Even if, for some reason, Apple decided to break from this general MO and release an HD anyway on current-gen hardware, who would really want it? Why buy a compromised product when you can wait for iPad 3 with next gen hardware driving it? I suspect what a lot of people are really asking for is a resolution bump with consistency in overall user experience holistically (and hopefully improvements, if possible), and that isn't going to be available this year. I imagine the same thing would occur to Apple.