I used to be a big PC Gamer when I didn't have kids or when I only had kid. These days, I occasionally fire up Counter Strike or better yet Team Fortress Classic (if anyone wants to play), and hang out with my buddies from Team Pfeffer (www.teampfeffer.com). My buddies and me have been running Valve based game servers since 1999, and dabbled in other such as Battlefield 1942/Desert Combat, Unreal, etc.
One of our Pfeffer guys (Mr, Bobby Peru), has written a lot of our own plugins using the SDK from Valve. This allows us to do things like limit the firepower of the winning team, or run a profanity filter. There are a lot of options "out of the box" on Valve's dedicated server, but the cool things come from writing our own plugins, etc. The big pain in the butt is that Valve games aren't really federated, and you need to sort through logs in order to pull stats on player performance.
Xbox Live provides an outstanding infrastructure for game developers to leverage, but it is unfortunate that it can't be tweaked. Xbox Live centrally collects stats, and lets game developers expose that through leader boards and their own GUI, but the engine is provided as part of the Xbox Live service to the developer. This doesn't allow much flexibility to implement new metrics or people the host games "tweak" the game to the point where you can consider it a "mod".
Xbox and Xbox Live is locked down for a reason, to tightly control the rampant cheating prevalent in PC based games where the host and server are loaded on your own client or server. A lot of the cheating that occurs is because someone finds a way to hack a DLL or memory and see through walls or write a script to aim quickly. Since the hardware and software on Xbox Live is locked down pretty well, most of the cheating that occurs is a bug in the game software and can easily be shimmed by a content download.
But..... A service such as Valve's Steam is delivering most of the feature Xbox Live delivers now, plus some very cool features such as never having to ever go to a store to buy a Valve game. Steam let's you purchase software online, chat with your buddies (although this is the lease reliable portion of Steam), and most importantly annoys cheaters so much by a fancy mechanism that changes server code constantly. Write a hack? It's worthless in a few days.
So, Valve to me is delivering the best of both worlds, and I would love the Xbox Live team to take a deeper look into the really cool features that are delivered through Steam. I think that a content deliver mechanism like Steam would only help Xbox consumers get what they want right now, and throw in some DRM to keep those games from ending up back at the used Game Store and you have a way to ensure that everyone always buys a full copy. Not to mention, that when you deliver content via Steam, the game developer gets a lot more $$ because they don't have to use a publisher.
BTW, looking forward to BF2 this week.