I took the next step last night - to try and connect to Xbox Live™... Not an easy problem because the router is upstairs (Xbox is downstairs), so I've bought a Wireless-G adapter. The adapter was easy to setup but connecting wasn't - reboot the router, modify the firewall, install a firmware upgrade (and panic when I then lost the internet completely).
I did manage to get connected but I think the delay on my broadband (it's via satellite) is going to cause issues. Whenever I play I get massive lag so as I move along I'll find myself back where I was a couple of seconds previously. I'm at a distinct disadvantage when going one-on-one with another player as I'll be shooting at their position 2 seconds prior.
I get two months of free trial so I'll see how things go. Hopefully everything will work OK because I guess I'll have completed the game in a few days and will need something to continue the interest. Check back in a month or so for progress.