6 hours play time for the singleplayer is just about what they said it would be.
The singleplayer content for all the COD games was always a bit on the short side.
I did a bit more reading about the setup for the MW2 servers in their current state.
Basically any match you connect to is being run off someones' machine. Local server I believe is the term.
So this means there's going to be much more lag with this game, and a lot of disconnects/ game interruptions.
This is due to the fact that most people don't build their PC's expecting to be a host for online play.
If you happen to be the lucky one picked as the host for the game, you're probably going to lag, unless you can support up to 18 players I believe, connecting to your PC.
Maybe Steam will be able to host servers for the game, I say this because I believe you have to activate the game through Steam, so there may be hope.
Another reason mod tools were not included, they plan to release DLC maps down the road, expect them in spring, which we will be able to buy...Yay!
For me, multiplayer is the reason to own this game, and they had the formula right with COD4, but MW2, does too many things wrong for me to justify dropping $60.00
on a game that graphically is identical to its predecessor. It only changes some of the ingame bonuses, locales and weapons and falls too short on the multiplayer setup
to  get my money.

Battlefield Bad Company 2 looks better and better every day, comes out March 2010.

I was talking to Servo yesterday. He bought it and said that although it was a good game, he'd completed the single player part in 6 hours. Yes, I did ask if he'd repeated the Doom 3 'cheat' experience, but he hadn't.

Oh, and I happen to know of someone that's got a dedicated server hack working, but is having trouble with the security side of it, and that's all I'm going to say in public. I'll let you know once they sort it out.

Well, unless they add support for dedicated servers and mod tools, I won't be buying this game.
Once again the PC community gets screwed.  Activision / Infinity Ward had almost perfected the formula for a great FPS with COD4.
Only thing missing was the option for an online Co-Op mode. They saw how popular COD4 was (which was developed for PC first, and ported to consoles second) and how much money it made them.
Then, they go and ballls the whole thing up with Modern Warfare 2 by making it for the consoles first and porting it to the PC.
Now, if you go to their forums and read all about the new implementations of MW2, you'll find they chose to use VAC this time around for their anti-cheat program. Big mistake.
All you have to do is go to you tube and watch the videos of players using aimbots  in online play during release week of the game.
I'm not saying punkbuster is any better an option for COD4, but playing on a modded server with all unlocks available from the start,
kinda defeats the purpose of players using hacks/cheats to try to improve their stats and perks.
Put it to you this way, when it was announced that MW2 would not have dedicated servers and mod tools,
several petitions were started on Infinity Ward forums, demanding - begging - pleading to have dedicated servers/mod tools patched into the game, reaching very high numbers of disappointed / pissed off players.
Mysteriously these petitions were deleted, and then started again, and then deleted, and then started yet again.   
For me the staying power and replayability of COD4 was playing on the modded servers.
Makes the game a bit more tense and exciting when you and everyone else doesn't know every choke point or sniping spot on the map.
Also playing the stock maps gets old all to quickly.
Don't get me wrong, this is not a rant, I think that COD4 in my opinion is the best FPS I have played EVER, and I'm sure that content wise
MW2 exceeds COD4 by leaps and bounds. My grief and disappointment is with the Devs dropping the ball.
My only hope for this game is that they will implement dedicated servers and mod tools down the road via a patch for download.
If that lucky day comes, I will scramble to the store to pick up my copy, and be a happy little gamer.
Until then, I'll stick with the tactical clan servers I play on for COD4.