Kopete webcam support is nothing new
But it's a new thing it's included as standard - I have read about versions of Kopete that should work with webcams before, just never the "official" branch. (You have to love OSS sometimes).
www.mercury.to the java based messenger (admittadly for MSN only)
Hm, I just read on their page that they will start supporting Jabber as well... still, I like using Kopete, so it's very unlikely I will change to another IM, unless they start getting broken protocols so chatting becomes impossible with users on MSN. But hey, sometimes it does break for some days after "upgrades" by Microsoft, so I might give this Mercury a try sometime :-)