I don't understand people who say things like "the high res display will cost more than the old low res one so the price will have to go up!".
If memory serves, and a quick web search seems to confirm this (though please do correct me if I'm wrong), the price, offline, of the 3GS at launch and the iPhone 4 at launch were pretty much exactly the same. In the UK that was about £500 for the 16 Gig versions.
Now, take into account inflation and that means the iPhone 4 was, in real terms, cheaper than the 3GS at launch despite the high res display, better camera system, front facing camera etc.
And this should surprise no one. The cost of the hardware is only one component of the pricing mix. By manufacturing more units the cost of tooling is reduced. Supply chains can be managed to reduce the cost of stock and increase efficiencies. By selling more units the cost of marketing and other costs of business are spread over more units and thus reduced per sale. Plus, for each new bit of tech that adds to the cost of the unit there's an older bit that gets cheaper and which isn't upgraded in any substantial way.
I suspect the iPad 3 will launch at the same price as the iPad 2 did. I hope that they will continue to sell the iPad 2 as a mid range product to entice those who might have gone for a Kindle Fire or another of these low end devices to upgrade to a full tablet experience. The iPad 2 is a fantastic bit of kit and is more than capable enough for most users. It would be a shame to put it out to pasture so early. And if we look at the iPhone (I know that's not a perfect match but still) we can see that the original iPhone lasted only one generation (was not kept on sale alongside the 3G) but the subsequent generations saw at least two models for sale at any given time - again, this may not be true in all regions but I'm pretty sure the 3G sold alongside the 3GS here in the UK. If the same pattern emergies it would be no shock.