Re: This just in...
The arguments against AI control of a character during lag are pretty convincing. I agree. Chaining commands is still an option, though -- for lag at 1-2 seconds, a player can fairly reliably predict what the battle is going to look like from one moment to the next (or rather, guess the differences between what is shown client-side versus what is actually happening server-side). The sudden 15 second pauses can still kill, but in my experience those usually precede a disconnect anyway.
So I'd consider playing if I can spam a series of actions that will take place in the order I request over a period of a few seconds, and if the attacks work without 100% accuracy on the clicks (since I'd be targetting opponents that appear in a different place than where I clicked 2 seconds ago).
But that just means I'd consider playing. I still wouldn't take the game seriously, or invest a lot of time into it. I'd mess around with some friends online, drinking a beer and laying down suppression fire while they do the real killing. I can see that being fun for a one-off weekend, and it would be worth the admission price (cost of the game). If, that is, my friends and I decide we want to play this--and I doubt that would be the case, since there are so many great alternatives (the lack of LAN play and max of only 4 players would probably knock D3 right out of consideration).
I doubt I'll ever try another MMO (my tolerance for multiplayer antics is limited to people I know, respect, and appreciate the humour of). The auction house, real money or not, doesn't really bother me one way or the other. The lack of assigning skill points I can deal with, too (plenty of great games that don't include customized skills). But cutting offline gaming? That eliminates my desire for singleplayer gaming--if I have to play online, I'm going to play with others.
D3 is targetting a very narrow niche. I'd play it only with 2-4 players (myself included), when we're all available to play at the same time, when we're not all accessible via LAN, when we all want to play a fantasy genre rogue-like click-fest action CRPG or whatever the term is now, when the Blizzard servers are available (since we can't host our own server), and when our ping rates are all within playable range (which, with chained commands, could be pretty laggy--but if it's auto-death like in D2 or D1, this alone could kill D3 as a viable alternative).
I just don't see any reason to buy this game yet. I mean, except to have it look pretty on my shelf, and to talk about with other people about how I'd like to play when those specific circumstances all align. The cost isn't an issue here--it's that Blizzard is eliminating my reason to purchase, because they're taking away my ability to play. With offline singleplayer, all those specific requirements affecting my ability to play disappear and it becomes just my choice, whenever I have the time. I'd buy the game without a second thought--it may be a bad game, but I'd take that risk in a heartbeat. $60 for a game that completes the series, which might be good or bad, but I can play whenever I want? Sure. $60 for a game that completes the series, which might be good or bad, and I can play when and for as long as Blizzard and my ISP make it possible and my friends make it worthwhile? No, not worth it because I know it'll sit on my shelf annoying me.
Anyway, Blizzard is a company and targetting a niche isn't necessarily a bad business decision--especially with an IP game like Diablo. Seems like a lot of people will buy into this model, and D3 will sell well no matter what they do because of the fan base. Whether or not it damages Blizzard's reputation remains to be seen. I imagine people who buy D3 will think they can play it, no matter how clearly they say it requires online play only, because it's not an MMO. MMO gamers know they're subject to the whims of the company, server, and Internet connection quality (and it's stated clearly on the product). If Blizzard doesn't make it extremely clear to consumers that this game for 1-4 players is subject to the same restrictions as an MMO, they may get some pretty negative feedback...