Doubtful. Apple mostly competes on the quality of the UI, platform integration, aesthetics/industrial design, and brand cachet rather than hardware. That isn't to say they use cruddy hardware; they don't. It just isn't the main manner in which they compete. Apple has a massive advantage over their competitors in terms of apps ecosystem, and at least arguably a fairly significant advantage in terms of overall look and feel of the iPad versus most of its competitors. Couple that with platform integration with other pieces of hardware and the result is many (if not most) people who buy these products don't see Apple's competitors are truly viable alternatives. There may be a few people on MacRumors willing to jump ship over a high resolution display but I would guess in general people will just wait for whenever Apple happens to deliver it in iPad form, so Apple has little incentive to release early and absorb the risks associated with having to stick in uprated current-gen architecture to support 4x resolution versus waiting for next-gen architecture next year which will be considerably more likely to provide a smooth transition in user experience (speed, battery life, etc.)
I'm not saying it's impossible; I just don't think there is as much of an imperative as some of the promoters of this rumor have suggested. It's conceivable that Apple may come out with such a device but, to be honest, I think a lot of people would end up waiting for the iPad 3 anyway if that were the case because of the above-mentioned point about underlying architecture.
