Steam is currently hosting a pretty sweet sale for Borderlands and associated DLC content; for ~$20 you can grab the game and all 3 DLC packs.
I decided to pick it up seeing as one of my co-workers is currently playing Borderlands and has been trying to convince me to play. It looks pretty interesting, I've had my eye on it for awhile but never got around to trying it out because of other games and such. I'm still working as much as I can on my Unity3d project, it's coming along but not as fast as I would like it to.
On the server front, I haven't made any decisions yet. I still want to get a server of some sort, but I've been putting off on it for the past few weeks.