There just isn't enough people queing up for this to be a good idea. Maybe if they start bringing out cross server Warzones, this could be possible. At the moment you only have a small population queing, the last thing you want to do is divide it up and make it smaller again. You would be waiting in line for ages.
BW probably have thought about this, you aren't the first person to bring it up. I personally hate Huttball (unless i'm in a pre made, then I love it), if I could que for PUG's without it, I totally would.