While we're sure that Apple is going to show off a new iPad at the announcement next week, it's not quite guaranteed yet that the iPad will have its own version of the Retina Display. Certainly there have been rumors to that effect, and it certainly would be cool, but we can't be sure just yet. Nevertheless, game developer Pixels on Toast has gone ahead and done the work anyway: They have screenshots over on this blog post that show what the company's next game, Food Run, would look like if it ran on a display with four times as many pixels as the current iPad's screen, or a resolution of 2048 x 1536.
As you can see above (especially when compared with the images in the post of the current iPad's screen), it looks pretty amazing. I remember when I first was buying my iPad, I had used the iPhone 4's display for quite a while, and I went back to the iPad and was disappointed that I could still see pixelation and artifacts after getting so used to the iPhone's screen. But if the Retina Display really did come across, the iPad's big screen would be brighter and clearer than most computer displays, making for some really incredible interfaces.
There are drawbacks, of course. In addition to the extra power required for such a display (both in terms of processing power and battery power), developers would have to deal with higher resolution graphics, in both 2D and 3D games. Devs have already gone through this process once, however, so most developers who already put iOS games together will have some idea of how to deal with the issue. Keep in mind, however, that bigger graphics means bigger files, so Apple may have to raise the limits on various app size requirements.
At any rate, the display pictures for Food Run certainly look, well, delicious. This is all speculative, but if Apple has indeed upgraded the display on the new iPad, there could be more exciting times ahead.