I did a fresh install of raspbmc-2013-12-23.img to a new B and got VNC working. Wired LAN connection.
If I go into any settings pane that, presumably, is going to download something like get addons etc. , I just get a blue pane with ".." no matter how long I leave it.
Live TV, having enabled just throws endless can't connect or dropped connect messages. It's not a firewall problem.
I tried the web browesr that did some sort of install and now if I click it the pi reboots.
TVCatchup won't install because of missing dependencies but they are in ~/.xbmc/addons as per docs.
So far not that impressed :-( My rasbian pi is much better behaved. :-)