In the first reveal of player-versus-player content, we get to see a European guild, Boon Control, challenge the talented developers of Guild Wars 2, ArenaNet. The video mostly features an Elementalist played by a developer. Thanks to Wartower.de for this high quality video. There is also an interview with Boon Control members on PvP.
The final PAX 2011 developer tournament that was recorded. I believe that there were roughly 8 more matches that weren't streamed over the internet. Who knows, maybe one day we'll get to see them.