I made this video to show what kind of potential a well (I think :P) played mage has. The video goes through every kind of aspect in PvP: 1v1, 1vM, AoE. Hopefully you can tell which section is which, lol. The 1v1s consist of well geared/skilled players. The 1vM fights range from 1v2 to 1v4 or more. The AoE consists of, well, PvP AoEing. There is also a bonus section at the end, which I got a kick out of making it and hopefully you'll get a kick out of watching.

I'm specced 21 arcane, 30 fire. My gear ranges from 300ish spellpower to 626 firepower 4% hit, 4% crit, 30 penetration.

Edit: Since I didn't make mention of the names of the songs/artists used in the video, here they are in order:

Hypnotize - System of a Down
Shinobi vs. Dragon Ninja - Lostprophets
Sun Doesn't Rise - Mushroomhead
Just Like You - Three Days Grace
Stricken - Disturbed
Crazy - Mushroomhead.