Is it worth joining?

I've been interested in investing in WoTLK realm for a long time but never found incentive to do so. I played Icecrown for a while but stopped playing at around 5.5k gs because of the difficulty to find a guild recruiting someone without 6k+ GS and HC achieves for anything. Also got dissuaded constantly from playing PvP because of the frustration of going against full Wraths with shadowmourne. In this regard is Lordaeron any different from Icecrown? Should I expect to see 9/10 players with shadowmourne?

PVP is cross-realm.

Buymourne is a plague that cannot be avoided, currently.

You could go for frostmourne since they havent progressed into the last patch yet if you want to avoid shadowmourne and the high GS wall and have a slightly easier time getting into raid pugs.
They also have a different pvp bracket atm.