Hey Nightfire, glad you had a good time your first weekend!
We talked about this quite a bit in the past, but we ultimately decided that we wanted players to be able to play the characters they wanted. The idea that someone on the other team can pick the character you wanted to play, ever though you worked hard to unlock them was not as appealing as just dealing with the "clone" issue. Think of it as Street Fighter, where you pick Ryu and your opponent does also - I don't think there's any strategic advantage for that, and you both get to play who you want!