Just call me Switzerland, I guess...
1. I have absolutely no doubt that the $60/$100 price tags are from the Activision side of the fence. (Insert animated .gif here of Bobby Kotick slavering over a calculator with a bottle of lotion nearby.) With DNF dead (for now, at least, and hush--it's just a frame of reference) SCII is the reigning Queen Mother of all highly-anticipated PC games. And Blizzard's going to make absolutely ridiculous amounts of money off this no matter what the price tag is, so in that respect they probably don't give a damn, but that arbitrary extra $10 just smacks of "because we can"--and that's definitely Activision's current agenda.
And yes, there's no doubt that someone's going to try to follow in AB's footsteps with that sort of pricing--EA, I imagine--and probably fail, for one reason or another.
2. And speaking for myself as someone who still remembers how much certain SNES games were back in the day and thus has a smidgen of perspective left: $10, at least in this specific case, is quibble-worthy--but not the end of the universe. (That said: even I can't quite justify $100 for the CE--though like just about every other CE Blizzard has made, it's going to get ridiculously overpriced in the aftermarket for about a year after release.)