I personally think leaving LAN out of SC2 is kinda a big mistake. Online play is still a main factor, but nothing beats getting a group of your friends into somebody's basement and having an awesome LAN party, complete with lots of pizza, beer, and five gallons of ice cream. If you think about it, the LAN party is sort of what started the decline of PC gaming. Back when the PC (and indeed, the RTS specifically) reigned supreme, it was the only platform that supported LAN. Then came the first Xbox and the first Halo game. Suddenly, the PC had some real competition, being as the main draw of Halo wasn't the single-player campaign which had been traditional for consoles up until that point, it was the "newfound" ability to get 16 people in one room for one giant profanity-loaded fragfest. This was the first sign of the decline of the PC, which was further accelerated with Halo 2, Xbox Live, and, later, the Xbox 360. All these things were great for gaming as a whole; more people play video games now then ever have before, but a lot of this has been at the expense of the system that started it all: the PC. With all this in mind, the lack of LAN support for SC2, which is probably the strongest PC offering in recent memory, is a huge step backward that will make PC gaming even less appealing. Hopefully, as brknarow pointed out, Stardock will be able to gain more momentum.
I hope that SC2 can deliver and revive not only the RTS, but PC gaming as a whole. I want a return to the Glory Days of Gaming, back when games like SC, Red Alert, Jedi Outcast, Homeworld, Diablo, and MechWarrior were the big guys. More importantly, I want Homeworld 3...