Lots of people still play Warband online. Few GON servers, a few GA servers (battle / DM mostly) as well as TGD duel server and some PWmod servers, and the odd Nord Invasion / other mod servers. No one is on during the day really, try night time.
I started playing the game when it was still Beta (around 2007 onward). It's been a couple of years since I've played it regularly, but I heard today that M&B 2 is in the pipeline. Something to look forward to, as it will most likely coincide with a new PC.