I'm not surprised he was nervous. Jonathan Ross can be a great interviewer because he's not too sycophantic (see his interview with Daniel on Film 2006) but on his own show he has a tendency to play to the crowd and often does or says the first thing he thinks off, which can on occasion make for some funny off-the cuff moments but it can also be absolutely mortifying!
He said some unnecessarily offensive stuff to Nicole Kidman when she was on before, really sexist I thought, like his joke yesterday

, and last week for no reason at all at the end of an interview with Jimmy Carr, the comedian, he started slagging off what Jimmy was wearing and then just lunged at him and ripped his shirt off!

Jimmy took it well but it was over the mark as far as I'm concerned, it stopped being funny and became bullying.
Daniel had a bit of that last night and understadably was a bit uncomfortable but he took it well and thankfully Jonathan didn't try anything stupid. Russell Brand can be annoying but I find him funny and I don't think the stuff he said about Daniel was too bad, if anything the fact that it got a good laugh at Daniel's expense made it unnecessary for Jonathan to do too much wacky stuff during Daniel's interview.
Not Daniel's best interview but could have been worse, nice seeing him on tv again anyway!