Blizz launches are notorious for these things. They fix 'em pretty fast, though.
Anyway, managed to get in and played through it....
It was a bit of a disappointment, actually. And I didn't have high hopes to begin with, so there was plenty of oppertunity to exceed my expectations. What bothered me the most was that the experience didn't seem polished at all - after StarCraft II's awesome in-engine cinematics, dumb as they may have been when you get down to the meat of it, the storytelling in this was an enormous step back and the voice acting was simply atrocious. Another big snag is that this is the normal mode, not the easiest mode, yet as someone who admits to having been terrible at Diablo I found this a cakewalk already. Not a good sign.
It also didn't really feel like Diablo at all. It reminded me of a game named "Silver" that I played years ago more than Diablo. And what is with the latest Blizzard games starting out with reenactments of the previous ones? I've already hunted down King Leoric, just like I already defended Mar Sara from a Zerg invasion. Why take a step back instead of continuing where you left off?