1280x1024
"With a 1280 by 1024-pixel work area for displaying your page layouts, digital image files and spreadsheets, the 17-inch Apple Studio Display features a screen resolution thats higher than you typically get with a 21-inch CRT behemoth"
Any 21", most 19" and some 17" CRT displays can display 1600x1200 pixels. flat displays typically have higher resolutions than similar-sized CRT, so I'd expect to get from this new display what I get from a 19" CRT - 1600x1200.
This is especially important since your typical $500 digicam today produces a 1600x1200 image, and since OSX uses larger screen elements than previous versions.
I use my 19" CRT with 1600x1200 for OSX and 1280x1024 for OS9. I would have liked to be able to do the same with a flat display. Definitely if I was paying a thousand bucks for it.