We already promised you that we’d have some heavy-hitters around on Wednesday night (July 20) to help announce the nominees for the 2011 mtv Video música Awards. But now we can reveal that at 11 p.m. ET, none other than Katy Perry will drop in to help make the announcement on mtv and stick around for a live-stream chat about them on MTV.com.

We’ll be visiting Perry — who has had a stellar ano since the release of Teenage Dream last August — in Seattle, the latest stop of her California Dreams summer blowout. And Perry will be just one of several special guests who will pop in to talk about the VMA nominations.

The nominations special and live stream will serve up even mais bold names as well as música experts employing Skype, Twitter and facebook to give post-VMA nominee-announcement commentary and reactions.

This year’s VMAs return once mais to Los Angeles, where the 28th annual show will air live on Sunday, August 28, from the Nokia Theatre in Los Angeles at 9 p.m. ET/PT.

To watch video of the biggest moments from last year’s VMAs, get the full list of last year’s show winners, and check out fashion, celebrity and música commentary from the show’s red carpet, check out VMA.MTV.com. And while you wait for the real voting to begin, head over to our Newsroom pesquisa to pick who you think should lead the nominations.