Now, first off I think Steam is brilliant, the concept of an online game library is brilliant as it sidesteps the twin woes of Scratched and Lost discs.
Being as everyone is pro-steam, however, it is my civic duty to point out the other side of the argument.
Yes, Steam is brilliant, and it has all your games stored on it, but think- what if Valve were to go into administration next month? What if EA managed to get enough cash together to buy out Valve, and decided to shut Steam down? I know it's unlikely to happen so quickly, but if Valve goes under it takes a HELL of a lot of money with it, as well as any chance you have of playing games.
Secondly, it requires you to connect to the internet to install even single player games. What happened to the good old days of popping in a disc and playing? Actually, on this point a friend of mine was moaning at me today about Steam. His problem? His copy of Empire TW had turned up one day before official release date. He put the disc in, and Steam refuse to let him install. In the old days, he would have been merrily playing it. Of course, it comes to release day, he installs it and Steam then has to download multitudes of patches so that he can use Steam, all so he can PLAY the bloody thing. With a console you throw it in the hole and off you go. Is this REALLY us drawing ordinary gamers back to the PC?
Lastly, Piracy. As I'm sure many of you know, I'm a self confessed pirate. I pirate games usually so I can find out if they will run on my system before I shell out on the D2D. With games like Saints Row 2, I will have to buy it and risk the game not working on my recently upgraded machine.