Princes seems to be the kind of fight where if you can make it to 50%, you should win not long thereafter. Nothing really changes about the fight. If your raid can handle the 3 scenarios with the 3 different Princes empowered, then there's nothing stopping you from winning.
Not a DPS race at all. At all. My guild is no paragon of DPS as you guys know and we had something like 5 minutes left on the enrage when we killed them. We even got the Orb Whisperer achievement, which is kinda a silly achievement considering it's what you're supposed to do anyway and not particularly difficult to begin with (see also: no dps race). Stress surviving over all else. It's fine if a dps has to run the hell all over and not contribute at all if it helps ensure they don't die.
Maybe it's just my guild, but I'm actually surprised by how easy they were. We had no practice with them on 10 mans, tried a slightly misguided attempt to tank Valanar and Taldaram with one tank for our first try, and four tries later had them dead. We had the Worst Rotface Kill In History just the day before, but I think we only had 2 people dead at the end of our Princes kill, and I didn't even use my battle rez cause the fight was won at that point. I'd definitely put the Princes below Rotface and probably Festergut, for my guild at least. Festergut will be a joke in 2 months' time whereas these Princes won't be much easier at all (without the incoming zone buff giving health, at least...) but eh, wasn't too bad.
Lana'thel, on the other hand... holy crap.
Though trying to move out of fires while healing dudes when I have 3 fps makes me a sad person. I lag so hard the first minute of some ICC boss fights...