As Prot I can get to phase 3 with no weapons up, however I can't kill Telonicus quickly enough. (Capernian's disorient is not resistible which sucks)
As Ret I can't live through phase 2 (which I find really odd as all the weapons are level 70, so they shouldn't really be able to touch me and I should be resisting everything).
I'm pretty sure I'll be able to get to phase 4 with 1-2 adds up as gear improves. What really is going to prevent Paladins from soloing this is the Arcane Disruption Kael is going to do. 10 second disorient twice a minute is going to make it impossible (unless its resistible, but even then... there isn't a good source of resist gear right now)