My little 10-person guild first started working on the Lich King in the late summer, right in the worst part of the summer slump. We were increasingly having to pug 1-3 spots, and then the Ruby Sanctum patch came down and broke everyone's addons, and the raid pretty much disintegrated. We've re-assembled since the 4.0 patch hit, and we're once again working on the Lich King.
It's a pretty tough fight, I must say, even with the 4.0 changes and the buff at a full 30%. We were at the point before where we were getting a pretty consistently clean phase 1, but we've had to pretty much entirely reconstruct that. Our previous OT had almost every drudge ghoul ever cemented to her face the second they spawned, which meant managing the horrors was a snap. Ah well, these things take practice and work. I think we can get him down before Cataclysm hits. I know that killing 10-person normal difficulty Lich King this late isn't a huge deal, but you know what? We first stepped into ICC as a guild wearing a bunch of stuff from heroics and item level 232 stuff, which was what you could farm from heroics at the time, and we've raided all of two nights a week. So I think we've done pretty well for ourselves.