I think MW2 as sold really well on the PC to date and will have very long legs indeed. I just believe steam sales are massive compared to retail sales.
I been a PC gamer for over 10 years now and I know a thing or two and If the game was released with dedicated servers we would be seeing alot of cracked servers up and hundreds of thousands of cracked MW2 versions out there all playing multiplayer (like COD4). And the game wouldn't of sold as many copies as it has or/is going too. Don't be fooled into thinking other companys won't be looking into this and thinking about having their own IWnet setup for online gaming.
PC gaming rules.....







