HapticSimian
Honorary Master
Is there any difference between this and the android market app?
It's just another way to access the Android Market. Once all the menus actually work, it'll be a helluva lot easier to navigate than the app on your phone, though. Reviews, screenshots, videos, application size etc. are quite a bit easier to check on a 17" PC monitor than on a 4" phone screen.
You can also push installations to your phone from your PC.