A few sites were able to go hands on with
Call of Duty: Black Ops recently but here's a
nice list compiled from those impressions on what we know so far. Of note, leaning is back in for multiplayer as well as vehicles. Also, the co-op campaign is going to be different from the single player campaign. By the way, the single player campaign looks to span a long time period instead of just one.
We all know that dedicated servers is back for the PCs, which is great but those that like the host migration set forth in Modern Warfare 2 can use that feature as well. I'm glad they are keeping both in as a choice but you know, I'm all about dedicated servers.
There are some nice little tidbits here so check it out and I'm sure you'll hear a lot more come E3.