I hadn't touched MP since the demo phase; my girlfriend raised a few characters, but I just didn't feel like going near it. While ME3's gunplay is quite fun, online shooters just aren't my thing.
I decided to give it another whirl for a while the other day, though, and I'm in the process of bringing my Soldier up to 20 again. (Had one there during the demo.) It's pretty darn fun, even if I know it won't be my cup of tea for long. The amount of maps, classes, weapons and powers really adds quite a bit of replay value.