Android does do this, but it only very rarely has worked for me. Like, take the Dropbox app, which is even listed under "featured tablet apps": you have file listings that are 8" wide, with no more content shown on a tablet than on a phone (which is just file name and icon).
A few, rare apps are usable scaled (ConnectBot is a good example), but almost nothing is ideal — or even usable — OOTB. At least with the ones I've tried.
Not really relevant, since there's enough iPad apps that it doesn't matter: I use one pixel-doubled app on the iPad (Facebook) and they're coming out with a native app very soon anyway.
A few, rare apps are usable scaled (ConnectBot is a good example), but almost nothing is ideal — or even usable — OOTB. At least with the ones I've tried.