You can now hide apps from your Mac App Store Purchased list. These buttons do not delete apps from your Mac, they just help keep your Purchased list tidy. I suspect the buttons are a new addition in 10.7.2, but I could be wrong. Anyone on 10.7.1 or earlier see them?
If you want to restore apps you’ve hidden, go to your account area, click “View Hidden Purchases,” and click the “Unhide” button.
I’m on OS X 10.6.8 and I can see those buttons. But I have a hunch that they can add features to the store without pushing out OS updates. They can do that with the iTunes store because it’s basically a website run through a webkit view. For example then they just added the Films tab to the iTunes store here in Denmark, no new version of iTunes, it just appeared one day. The Mac App Store is probably similar.
