Almost every game in the world has some form of DRM. DRM is a necessary evil, as the world thinks everything should be free. I don't necessarily agree with all the directions that Blizzard has taken, but if you say you were going to buy a game or not because of DRM, you were probably never going to buy the game. You were very likely going to download it because you knew it would be readily available.
Stardock's Demigod is an interesting case. The game shipped without DRM. 100,000+ downloads within a week caused the servers to shutdown and crash constantly, because they forgot to properly block people even trying to access the servers. A company goes the way of supporting non-DRM methods and ends up paying dearly for it with an unplayable game for those who went out and purchased legitimate copies of the game.
If you go on a LAN tunneling type service, such as Garena or Gameranger, there are thousands upon thousands (maybe a million across all different games and services) that have illegally downloaded the game and play it on these workarounds. If you think about it, perhaps as much as 50% of a game's audience may be people who have downloaded the game illegitimately, and I'm pretty sure any game company is willing to sacrifice the so-stating 5% of people who absolutely refuse to buy a game because of DRM.
My hope is that the DRM that loads up with Starcraft is a simple, smart system. I personally love Steam, as it doesn't require me to keep a bunch of crappy space-wasting disks or remember obscure passwords and logins or have CD-keys written on scraps of paper.