Observe:
Exhibit A:

Exhibit B:

As you can see, neither is overly thrilled with the idea. (Though really, I feel Vash would be trading up...Kyuzo doesn't seem to think wiping out planets is a fun passtime...course, he's probably be just as into the idea of fighting Vash to the death as he would Kambei...)
It's like Vash forgot the hair gel. And how to smile.
ETA: I just realized that, aside fromt he recent GitS movie, this is my first anime since I watched Gungrave, which was back in...what...June? Maybe July? That's a LONG break for me...