How to (legally) remove Singstar from PS3
Solution 1:
Not an ideal fix, and probably less legal than desired, but the Singstar icon is not present in the PS3 XMB when used with a non-"European" PSN account which is easy to create under a new Profile using an American address during signup.
As I said, not ideal as you are creating a whole new PSN ID just to avoid seeing the Singstar "ad" under that profile only.