You can now remove games from your trophy list if you have a PSVita

[Mavrick]

The latest Vita firmware update (2.60) added the option to remove games from your public trophy list.
(in your friends list, or for example at http://psnprofiles.com/Nickname)

How?

Using a PSVITA, simply go to the trophy app, make sure you're in the PSN column, and click a game.
Then click (...) in the bottom right corner and select [Privacy Settings].

As reported on Gaf