As long as there's dedicated servers and the players aren't bullet sponges, I might consider getting it.
And in the discussion, if something is fun and works, I don't need anything new coming to the table. I played the original Modern Warfare, and that was fun. I have not played MW2 because there weren't servers, but I do like modern shooters. I don't need innovation or shiny new goodness every time a game comes out. If the Killzone series had a bunch of full length purchasable add-on campaigns that didn't add any new mechanic I'd still pay money for them.
When CoD:Black Ops and Medal of Honor are out (if MoH has servers) I'll compare them, and figure out which I like better, depending on the options, customization, and overall feel to the game.