Yeah, for sure! It's great to see a lot more events happening now. There's a pretty great Facebook group of all the 'Hackathon Hackers' in the UK too: https://www.facebook.com/groups/hackathonhackersuk/
I think we have the rivalry part pretty much nailed, especially in London ;)
Really eager to see more on the collaboration side - societies working together to support the greater community: traditional CS backgrounds or not.
Do you have the name of that IRC channel?
details are http://www.compsocs.uk/
There are quite a few computer science oriented student societies. For instance, at York (where I did my undergrad) there's HackSoc. There's an IRC channel somewhere on freenode with computer science societies from the uk. We're not completely disconnected, but we're slowly growing to the point that we can start collaborating and having friendly competitions.