Things like this are why I haven't bought HL2 yet.... and it's killing me!
I like the idea of controlling cheating online, but offline - stay away. I think how it's been done with the original HL or UT2KX where you can be banned based on CD/WON/<X> key from servers, but it's still yours to use as you want, is my preferred method.
At face value, I love the idea of being able to dl a game... but I'm afraid that the heart is rotten and gives the publisher too much control over what they want me to buy.
When I go into a store, I want to buy the game. Steam appears to be more like an extended rental at the moment.
I almost expect there to be at "Insert Coin to Continue" the when you die in HL3. (Fully linked to the credit card on your steam account, of course.

)
Perhaps things will get worked out in the future, but for now I stay on the sidelines and try not to be bitter at Valve.
Wiwi
"I trust in my abilites,
but I want more then they offer"