Latest news (possibly unreliable, but I think it's supposed to be pretty solid) is that Billie signed on for the whole second season. Jack also is supposed to be back in the second half.
On a side note, I really like that "Every Me Every You" video you did; in fact, a while ago I watched a lot of your older Buffy/Angel vids and now's a good a time as any to say that you're easily the best vidder I've seen.
So you should make a Who vid, so I have something good to watch :-) The Who fans try, but...it doesn't always work out.