Many people do not participate in WvW because of the extreme lag they receive. By adding a lot more champs although it would be awesome, yes… It would not bring in a lot of people (well at least not in the long term) as the lag for many would be un-bearable. In fact that could lose many players, ever hard core WvW players:/
I say what must be added to WvW is more variety, More tactics and above all… Some sort of help for the new players that get thrown in at the deep end.
Ps. Commander Rank should be only available in (world v world) to those who has an experienced rank, so that people like me, are not following inexperienced rich boys who think they can run around with a fancy icon and send us all too are doom.