As someone whose faction falls on the other end, I can say that this will definitely encourage me to PvP more. In fact, I would say that there is enough of a positive feedback loop for those factions who normally lose WG on live that there will be a balancing effect in encouraging more people who normally lose to continue doing it because they know that the other faction will not out number them three to one.

Kinda like the Halion fight, balancing between the two phases and balancing between those who win and who lose. Does that WoW analogy make sense?

Yeah, I expect the same for me only Horde-side.

It might have some positive benefits though. With Wintergrasp, you'd often have people faction changing to be on the side that dominated Wintergrasp, or people looking to transfer to a new realm wouldn't want to transfer somewhere where they'd never win Wintergrasp. With any luck, this trend of making the dominant faction more dominant will end, or at least slow down.

Even though it'll be hard for me to get into Tol Barad with this change, I still think the battles I get in will be a lot better as a result. Tenacity was a failed mechanic that resulted in a frustrating game for the smaller team and a boring game for the larger team.

As someone whose faction falls on the other end, I can say that this will definitely encourage me to PvP more. In fact, I would say that there is enough of a positive feedback loop for those factions who normally lose WG on live that there will be a balancing effect in encouraging more people who normally lose to continue doing it because they know that the other faction will not out number them three to one.

Kinda like the Halion fight, balancing between the two phases and balancing between those who win and who lose. Does that WoW analogy make sense?

I'm not sure is 1:1 on beta but in beta the battles go like this still:
40 horde vs 10 alliance and some unknown amount hiding on the map.. Alliance(attackers usually in beta) spawns at the bridge in north (see image 34 of 36) while horde(defenders usually in beta) spawns at middle instantly going to the bridge camping spawners and their GY for 20 minutes..well they are still immune at GY but unable to do anything at all.
Only at late there has been actual wins for alliance at all.

So I'm not totally sure is the balance going to work like in beta or is that just different case due noone actually wanting to play alliance on beta.

It will still need a lot of balancing in beta and will most likely not be totally balanced on first patch (like wg wasnt until something like 3.3..)

Many previously balanced servers (like mine) became imbalances because of two things: great WG loot, and allowing paid faction transfers.

Faction transfers aren't going away (too much money involved!) so the least Blizz can do is ensure overpopulated factions don't have an unfair advantage, with almost constant TB eaid access.