We all had those dreams with boomkins. Sadly, unless there have been some recent changes (haven't played in about 2 months) currently boomkins are not great for multiboxing PvP compared to other options (shamans of course, but apparently pallys and DKs work very well together). Our owl friends lack the burst damage to really make their mark and they are too squishy when they try to heal.

It was fun running 5 boomkins in AV and hiding in the hills during a big fight one shotting everything that came in range. However, unless you have the time to properly set up on some unsuspecting enemies, the moonkins just don't have the burst to work well together.