PS3 owners in Europe, Australia and New Zealand have the option of installing SingStar straight from the XMB. The core game is free, but you will have to purchase full versions of songs for the complete experience. SingStar does come with demo versions of some tracks to get your started.
The downloadable version of SingStar also supports SingStar PS2 discs regardless of what PS3 you’re using. The PS3 won’t let you store songs from the PS2 onto your hard drive, but it can read the song data when the disc is inserted. If you downloaded SingStar tracks that are on another PS3, you may need to contact Sony since songs are tied to the console and not your PSN account. If you’re fortunate, Sony may let you download those tracks again.
SingStar can be played with a variety of USB microphones, or you can use the PlayStation Eye camera for single-player sessions. This version of the game also comes with new trophies and the ability to create playlists on the Vita.
Source [European PlayStation Blog]