Can I use a retina display at actual pixel size? Unfortunately I just learned that Apple is has already discontinued the 17" MBP and Apple marketing has this quote:


  But if you’re looking for a reason why Apple offed the 17-inch now, you need go no further than the 15-inch Retina display MacBook Pro. Not only does it offer the most cutting edge technology of any Apple laptop to date, but its 2880-by-1800 pixel display outstrips the 17-inch’s 1920-by-1200 resolution with room to spare


The numbers quotes are a larger pixel count than the 17 inch model allowed even with the hi-res display but I haven't played with or seen a MB retina display in person yet. Can I set the pixels to "actual size" so that when I do web design I can have a browser set to normal scale but see a LOT of the web page - or for that matter, any app?

I like the idea of a Retina display but if I can't set the display to show the pixels at "actual size" it seems like I am in fact still losing screen real estate even though there are "more pixels" if that makes sense.
Yes you can, but you probably will not choose to do so. When you really want to force the display into 2880x1800 you can easily configure it that way. Here are four of the better options available today to do what you ask:


SwitchResX
Retina DisplayMenu (used to be SetResX)
scrutil
ChangeResolution


That said, items like the menu bar with the Apple icon are extremely small at 2880x1800 and you don't need the entire screen to at that high resolution for a properly build application to let the windows it controls have the full resolution. The scaling modes are pretty good, and you can always reduce your font sizes even while running at the doubled 1440x900 resolution. Most people will never need to set 2880x1800 since they really only care that the applications they use get the retina treatment and don't need to force the rest of the UI to run with such a dense packing of pixels.