Well, while it can be retarded to have someone drop in a global or two...
They won't want to go with the opposite route too far, as players are going to really hate the shortest matches being in the 10-15 minute range.
There will be a happy medium somewhere.

We still retain the advantage of coordination and burst vs single box teams.
And are still lacking in simultaneous different actions by toons.

The other consideration is rated battlegrounds.
Surely we'll have the burst to take out individual players without healer support.
But the question becomes, can our group of five take out more then five at once in BG's.

Wherever we have a larger advantage, that's where we will play.
Arena and BG's give more options for attaining a high rating.