Picked it up at the midnight release, along with like 20ish other people from my dorm
at which point I played it (no joke) for 4 hours straight before deciding SOME sleep was necessary.
Honestly, both my roommate and I have been following the reviews online (going from "meh it's not what we were expecting" to the now hordes of angry kids going from site to site giving it 1 star ratings), and neither of us can see where they're coming from. Sure it might not be as challenging as Starcraft II, but everything up to the Space stage is just straight up FUN. I plan on going through at least a few more times, if not to just watch the creatures interact some more.
However, the Space stage is insane. They could have released this standalone as a totally different game (call it "Galaxies" or something) and it would be phenomenal. It's kinda similar to Eve Online, but without the tedious boringness. It's just unbelievably open-ended; it might seem kinda random at first, but once you start getting into it (making alliances, warring with enemy alliances, etc) it's just unlike anything I've ever played before.
Verdict? GO BUY IT NOW
(oh also, anybody who already has it, post up your username so we can subscribe/buddy/whatever they're calling it. GeeForce here
)