Today I played 50 matches of arena in the 1500 or so ratings. We fought:
25 Priests
15 Druids
15 Death Knights
15 Warriors
15 Rogues
....
3 Shamans
1 Hunter
1 Mage
1 Warlock
...
0 Spriests, Boomkins, Protection warriors or paladins, frost or blood dks, enhancement shamans, etc.
...
there are 10 classes in World of Warcraft with 30 different specs not including hybrids. Yet we have to play the same 5-6 specs over and over and over. This is not enjoyable. If Blizzard doesn't do something to address the fact that half of the classes are not viable and melee completely dominating, Arena will die out.