Opening of the Dark Portal

At 85 this is a complete joke. It's also the best way to farm rep with the Keepers of Time.

I just tried to solo this as a level 80 boomkin in ICC 25 gear. I was kind of surprised when I began getting overwhelmed with adds, and realized that I was almost out of mana. Anyone have any luck soloing this place?

Yeah, I solo it all the time on my Hunter. It isn't hard. I can even stay in Viper and still rotflstomp them into the ground. Doesn't even matter what pet I use, either. The key is preparation for the wave and proper use of aggro management and AoE. If you prepare properly, you shouldn't have any issues soloing it at 80 on any class. I did it with my Prot Warrior, too. Not even in ICC gear. Bring a few health and/or mana pots if you like. They aren't needed, but they make the fight easier.