I hate to bump a slightly (one month) old thread, but it looks like a few people were interested in this.

I have some news, whether you feel it will be good or bad is up to you.

I am currently developing an application for Harmattan and MeeGo that will be like "I am T-Pain" or "Glee Karaoke" (both applications for the iPhone). The first version will most likely just allow you to record yourself and then autotune your voice - further versions will allow you to sing along to a song, have the lyrics show etc.

I am unable to port it back to Maemo 5 due to my N900 being drowned by a family member (a little one), but it will be open source and should be pretty simple for someone to port back.