You guys understand that "lack of dedicated servers" doesn't mean "peer-to-peer", right?
It basically means that the "server" will be determined as the group of peers gets together, and will be "traded" to another peer, if the original "server" leaves the game.
This is part if IW's attempt to stop games from ending, just because the server left, which is something of a "cheating" mechanism for people playing on a dedicated host.
This way, yes, there will be a lag advantage, but it will probably be only for the guy who had the best (upload -- i.e. server bandwidth) connection to begin with (i.e. the guy would would have already had the lowest pings), and the rest of the game will be better off for it, because the best, of all players, would be chosen as the server, rather than some guy (who intentionally wants a lag advantage) with a cruddy connection.
Allowing the game to choose who the server is, is probably the best option for everyone playing, on the whole. The one, and only, better option would be to somehow guarantee that the dedicated server had colossal bandwidth -- in other words, was set up by a business, or by the game publisher themselves (like many of EA's games, like BF1943, or BF:BC, which have at least a few "big" dedicated servers, or Sony's games, like Warhawk, MAG, and SOCOM, etc, which are all "big" dedicated servers).
