Future proof? In electronics? Surely you jest.
2560x1600 is the way to go, more screen space when you're not gaming is very welcome.
It also makes people have to stay on top of video cards to run games, which not everyone can afford to do.
16:9 screens are cheaper to produce, so that's where you'll see most manufacturer's lean toward. As far as furture proofing goes, I wouldn't worry about it.
This. I don't like 16:9 that much, but for the sake of lower prices, I think it's fine that almost everything gets tooled for 16:9 and that 16:10 carries a price premium. 1080p panels are high-volume parts. I suspect 1920x1200 are far lower volume and that companies don't want to have to retool specifically for those panels. Better to just run everything through at 16:9 to capture economies of scale better.
Future proof? In electronics? Surely you jest.
2560x1600 is the way to go, more screen space when you're not gaming is very welcome.
To my mind, the more pixels, the better. Vertical is a more pressing concern in larger screens because human beings like to read vertically (take a look at your books, magazines, web pages... how many are wider than they are tall?), but most panels are wide. It's easier for eyes to scan down than to sweep left to right over a large expanse. That's one of the reasons why the iPad and other slate/tablets make for easier web-browsing and text-reading than similar resolution but horizontally oriented netbooks.