[quote name='Nesrie']Question. If i buy Left 4 Dead 2 and Register it with steam, I can then download it from Steam again if I need too and not need to buy that silly extended download thing from EA?[/QUOTE]
Not only can you, but you have to. Retail copies of L4D2, like all Valve games since HL2, must be activated on a Steam account, which they will then be permanently attached to.
Note that the EA Store is not selling downloadable copies of L4D2; EA is just the distributor of the physical retail version, which is what they're selling.
[quote name='tooshorty6432168']I've never downloaded anything from them. Are you sure it's an actual application that you need to play their games through, or could it just be a download manager for the games files that you never need to touch again after the initial download?[/QUOTE]
If I'm not mistaken, you just use it to download the installer, basically, but I could be very, very wrong.