I think his career is on the decline. Like many in Hollywood, though, it won't be permanent, but he'll have to lay low for a while and nix any current projects he was hopeful for. The Buffy reboot may be the one thing that could save him, but it's going to have to be done very very well, and I don't have high expectations of that happening.
Even in past interviews, he strikes me as being a twit who is embedded too far up his own ass, and way too impressed with himself. I can also see him being a tyrant on set. However, his work on Buffy was really good, very entertaining, and original.
Plus, if you are involved with the arts, temperaments and bad behavior goes with the territory. I've had dance mistresses tear my muscles while forcing a stretch that I wasn't prepared for. I've been called everything but a human being while playing first violin for two separate orchestras, and I've been on stage while a director threw a chair at someone else. It's the nature of the beast. So long as the product turns out exceptional, it's all worth it, but when someone's personal issues start working into the art like a political ad, then it's game over. I don't mind a jerk, just make sure the product is good.