Patch 1.8 available for download.

[lemekim]

In order to keep teams in Alterac Valley more numerically balanced, players will now enter Alterac Valley on a one-for-one basis (i.e. if there are 30 players in the battleground for each side with 10 players in the Alliance queue and 2 players in the Horde queue, only two players from each team will be added, bringing the total to 32 per side).

I wonder if they fixed "Join as Group" option working with low levels, or did they just leave the lazy fix of not being able to join as a group altogether =\.