If he was talking about a future QuakeCon, wouldn't he say future QuakeCon or QuakeCon 2011?
I think so. He came on stage for 5 minutes max, as an introductory speaker before Carmack's keynote began. I think he wanted to get the Arkane announcement out there and hint at the goodies in store for the weekend.
It may well be a new game entirely rather than TES:V, and the 'working together with Bethesda' part of his speech may have been referring to nothing more than a developer/publisher partnership. If that's the case, then it's just yet another game for Beth to publish whilst their internal team remains at hard work on TES:V.