I'm excited about the expansion. I'm going to try to go slowly through the experience - I finished Leviathan all in one sitting and while it was fun, it was over too quickly.
I may also try to finish off the game again after completing Omega - after doing the Leviathan and Omega expansions I am hopeful I'll be able to make it to level 60 and get that achievement. Although I cringe thinking about trying to survive that last battle again.