I'm actually very impressed by how precisely Blizzard nailed the balance they had to have. From the beta, it feels very much like StarCraft 1, but at the same time it's *not* like StarCraft 1. It's a strange mix between familiarity and "whoa, all these new abilities and units change it up entirely." It's considerably more different than I think many people give it credit for at first glance.
Also, I believe that SC2 won't get pirated as much as other games, just because you are actively getting an inferior product. The only benefit is that you get a hacked-in LAN, and get to play with the other few thousand people who pirate (where games can be hacked/cheated, etc). Whereas people who buy the game legitimately get the new and improved Battle.net, a much wider playerbase, a better browser for custom games, all the stat tracking, etc.
Unlike many other products with restrictive DRM, the pirate doesn't get the better copy of SC2. His copy is much worse.