In its latest update, Android Market is pretty much starting over. All of the gazillion apps are still there but the interface will look different and the experience will almost be brand new.
On the home screen of the Android Market, a new carousel feature let's users flip through featured apps in a Cover Flow-like style. Google has also added new categories for Live Wallpapers and Widgets and promises more categories for popular apps in the future, too. Once you get to an app's page, you'll no longer see the old tabbed interface but rather a single, "streamlined" page. There's also a heavier use of green, if you hadn't noticed that.
Google will also change the refund time of apps from 24 hours to 15 minutes, so no more gaming the system. They're also upping the maximum download file to 50MB in hopes of landing richer games and offering better support for different screen resolutions and such.
These tweaks and changes all add up to one of the biggest updates to the Android Market since paid apps were introduced. Google says that this brand new Android Market will be rolling out to Android 1.6+ users in the next couple of weeks. [Android Developers Blog]