I like seeing my opponents before the gates open. My concern is that you will have to respec/glyph frequently and that it will cost money. I also bet you'll find people start waiting until the last second to change spec - hopefully they restrict that so you're locked in for the last 15 secs or so and make respec/glyph free inside the starting area.
you will have to respec/glyph frequently and that it will cost money.
this is a design goal, to have the ability to. That doesn't mean you'll "have to". Both sides will only be guessing at which talents/abilities the other actually have. Remember, you won't be seeing (Ret Paladin 2/7/32)...