This just in, the group known as All Time Low is currently working alongside with EA to have one of their songs recorded in Simlish, according to Frontman Alex Gaskarth.  He posted the following on his Twitter account:

Recording in Simlish. This is ridic. – AlexAllTimeLow

No word on what the song may be – its speculated it could be a song from their upcoming album, Dirty Work.  More than likely it will be featured on the 4th expansion pack.

Source:  Kerrang