Apparently, John Carmack agrees!
 
Personally, I agree with him. Before the hardcore PC gamers chew me out, I want to make it clear that I grew up on Quake and UT and I used to swear by that model. But over the last 2-3 years, I've had a better experience with games that use a matchmaking system instead. It started slow with Halo and I was initially annoyed by the constant lag and dropped games but with time, the overall experience has almost caught up with dedicated servers while still maintaining the inherent accessible nature. I'm still very much a PC gamer but I constantly envy some of the console matchmaking features.
 
I think Carmack and the whole MW2 scenario indicate that we are at a tipping point where developers can fully commit to a matchmaking system and still provide a great multiplayer experience.
 
An important part of the puzzle that a few people miss is that almost everyone has cable internet connections now and even the base hardware running these games have improved drastically over the last 3-4 years to an extent that you can host and still play at the same time. Modern desktops/laptops, Xbox360 and PS3 are mighty machines with some serious performance and we no longer need to spend four grands to host a video game.Dedicated servers were born out of technical restrictions imposed by the old 90's hardware. Even the internet infrastructure at the time wasn't conducive to online gaming. You needed a heavy duty system using office lines to run stable Q2 games but times have changed.

 The other issue is the community. Dedicated servers indirectly led to the creation of clans and online communities based around a single set of servers. But whats to say the same kind of close-nit community can't be accomplished with a matchmaking system ? I can't speak with any authority here since I tend to meander around when it comes to games but I can site a couple of examples here. Street Fighter had a very active community scene with the arcades which acted like a server host for everyone to hang around and meet up for games. But they have transitioned really well to the current matchmaking system used on XBL and PSN and you see a lot of people who first played on these networks randomly, liked what they saw and went on to form their own fight game clans and such. The arcades scene is still alive but the torch has been passed to the console version so to speak. The second example I have is Forza which is another game that uses the matchmaking system with an active community. Forums, group and ingame chats are a few ways I can think of that can help sustain a sense of community in these games.
 
Performance is another caveat that stops people from fully endorsing the matchmaking system. I'll admit that a fully dedicated server is still going to outperform a p2p based system in sheer numbers but how much of that translates into the actual game ? Is the extra 50ms worth all the hassle an average user has to put up with ? And look at it from a developer's point of view - the amount of control they get interms of content delivery when everything goes through them. Being a programmer myself, I'm very much for anything that gives the original developers as much control over their product as possible without stifling the community. We will see how IWnet turns out but I've high hopes for it. 
 
Sadly, the demise of dedicated servers will hurt the mod community the most. If there was one thing I could carry over from the dedicated servers, it would be the mods. 
My favorite multiplayer moments have occurred when I was playing modded versions of Q3 or UT2k4 and I wonder how they will adapt.