There is a new version of the Android Market app available for download now. It's a challenge to see how it is different, because it looks identical, but from the reports we have been hearing, it is faster. This leads us to believe that the primary changes they made were simply optimizations and improvements for performance. If you notice anything else that seems different sound off in the forums. Here's a download link below, and a source link to XDA for originally finding the story.
Download: Android Market App Version 3.1.5