/sigh blizzard... really? really?
This could be trouble for pvp. Counterstrike source was implemented in a similar fashion, any one familiar with cs and cs:source knows how much it can suck some times. Shooting some one in the head, seeing the blood appear on their head, and then falling over dead yourself while your opponent walks away unharmed was not fun in source. I can see the same shit happening in d3 pvp, you cast some rape meteor on that barb, you see it hit him, but wait just kidding! Server says he was 3 yards to the left, and he threw an ax and killed you before you even cast meteor.
If you've got high latency then, either way, you're fucked. It's not like the original system meant things worked properly with a full second of lag.
True, its more of a frustration thing for the users. IMO its much better to have everything freeze up in the traditional "lagging" sense, than it is to think you shot some one only to find out you didn't. Diablo pvp probably wont move near as fast as CS:S does, only has to deal with 4(?) clients at a time, or need the kind of pinpoint precision a fps does so unless blizzard really fails it will probably be fine.
BTW if any one is interested in technical details of how ummm.. messy.. (at least in the source engine) a similar implementation is, check this out. Its probably not to relevant, but some one might find it interesting: http://developer.valvesoftware.com/wiki ... prediction
On topic, I wonder how the RNG will work. Will the client/server share the same one, or will the client could report the seed it used to do each batch of calculations, or maybe the server still does all the RNG some how. If the client reports its seed, figure out a few known seeds that make the next series of hits become crits, send the spoof rng and the "better" results. This whole thing feels like a massive can of worms.