When Will Empty BGs Be a Concern?

It's 6pm on the Retaliation battlegroup, and there is:

1 (one) Isle of Conquest running - upon joining, it has been 27v40 for the past 13 minutes.
2 (two) Stands of the Ancients running.
1 (one) Eye of the Storm running - last 10 people waited four minutes according to the icon.
7 (seven) Arathi Basins running - it is the daily.
2 (two) Alterac Valleys running.
13 (thirteen) Warsong Gulchs running - technically it's the holiday BG, but it usually has 10-15 running always.

Even if Cataclysm does not introduce any new BGs (which it is going to do), there is clearly a problem with filling the battlegrounds we have already. When will this become a priority, especially in terms of Isle of Conquest starting with, say, 40 Horde versus 15 Alliance for the first seven minutes of the game? If you are concerned that if the honor token turn-in quest was changed to six of any type of token would further erode, say, anyone queuing for EotS or Strands or Isle, then what does that really tell you about those battlegrounds compared to WSG?

I think the only real option here is introduce cross-battlegroup BGs, but only for EotS, Strands, and Isle of Conquest - leave the popular BGs and Arenas to be within their own battlegroup.