I'm not familiar with muzu.tv (I'm in Canada), but if this is a reputable site, it's odd that whoever uploaded that information did so without approval from Capitol/EMI, and has not been taken down yet to quell further speculation.
I also did a scan of ATRL and Google and I have not picked up any official (or semi-official) news about Part Of Me being released as a single, except for what has been posted on the fan message boards, so my skepticism remains high.
However, what is
interesting is that YouTube appears to have taken down any clips of Part Of Me due to "copyright violations reported by EMI". I noticed this on a thread which features the POM YouTube clip:http://katyperryforum.com/index.php?topic=9271.0
Historically, this usually means that a song is being prepared for a single release. I note they have done this with ET, LFN and TOTGA just before their releases.
So it appears that Katy and/or Capitol/EMI have some plans for this song? Perhaps a release in conjunction with the Sims Showtime release?
Either way, this is one kickass song! Kinda sums up what Katy has been going through/feeling these past couple of months. It's become somewhat of a personal anthem, similar to Kelly Clarkson's What Doesn't Kill You. I for one would be excited for it's release!