One of the things you may have noticed in my Dell Streak vs Droid X, HTC EVO, and Samsung Captivate posts is that although the screen resolutions are either identical (800 x 480) or very similar (Droid X: 854 x 480), more text is displayed in Android Market on the Streak in portrait mode.
Ten apps can be viewed on the Streak, while just six apps can be viewed on the other phones.
Although this is supposed to be an advantage of the Streak's large screen, allowing people to see more apps at once, browsing Android Market in portrait mode is currently very flawed on the device. Ten apps are shown at once, yes, but there's no way to see any more than that because you can't scroll down. It's as though there are only ten apps available in every category. Flip the Streak into landscape mode, however, and you can scroll through hundreds/thousands of apps.
This issue is better seen than described, so watch the video below for a quick demo.
A software update should be able to fix this very easily.
Update: It's been fixed in Android 2.1 (thanks, Ben)