I know I had one issue where wow would crash every time I logged off a character. It turned out to be either Recount or AtlasLoot. Both were updated quite quickly and the issue has gone.
Not had any trouble logging in though.
Try deleting your addons as Aph said. Or better just cut and paste the addon folder somewhere safe and try that. If it works, you know its an addon. If it doesn't, then you have your addons all safe to put back in.
Zalid - 90 Fire/Arcane Mage (Enchanting/Tailoring) Armory
Welsh, and proud of it. Cymru am byth.