I didn't get a chance to do much with wizards during the open beta. Just enough to make one and to play with a few starter skills. That said, i did notice that AP seemed to regen surprisingly quickly.
It's not enough to be able to constantly spend it without running out, but it did seem to be enough to be able to spend about half your time casting.
Looking around, every build I've seen seems to rely on 1 AP generator. Why? I mean, in harder content we'll probably be spending as much time moving around as we do casting in combat. Would it be worth it to sacrifice an AP generator for, say, a nuke of an element you haven't touched yet or another utility? What do the more experienced players here think?
Edit: Also, worth mentioning diamond skin + prism, astral presence and power hungry passives, etc.
You mean not using a signature skill? With some active or passive skills (like the ones you mentioned) and items (AP on crit, +max AP) it may be possible. On the other hand, doing that may restrict our choices too much. I'm sure many people will try to do this, but it remains to be seen whether it's a viable way to play or not.
I'd say that a signature skill is important if you want a good build. If there are ever any moments when you can't cast a spell, wasting that weapon swing is a huge DPS loss - you should be casting something at every possible opportunity, and there's no spender so cheap that you could cast indefinitely.
It seems like while AP regens fast enough, it's also not that hard to run out of it and still have time to fill in with a signature spell. Some builds will depend on signature spells more than others (ex: meteor builds need them badly, while ray of frost builds won't use them as much), but they'll all find themselves casting them. Even with all the running around, I find it hard to believe we'll run around so much 100% of the time to never really run out of AP. If we do, then Blizzard did a bad job. Even in the beta, where 2-3 arcane orbs pretty much clean house and then you're off running to the next pack that you start with full AP again, I found myself finishing monsters off with the signature spell because my AP was still regenerating. In other words, we'll probably run around a lot, yes, but probably not enough as to never run out of AP.
The real question is to me, though, not whether we'll use the signature skills or not, but rather will we use them enough to justify stuff like the "generate 4 arcane power when dealing damage with signature spell" passive. I wonder what % they'll be of our overall damage (probably not a whole lot but still a meaningful amount), and how that will affect weapon choices - While slower weapons with equal DPS are obviously preferable for the wizard due to AP efficiency, if the faster weapon has more DPS it becomes a more difficult choice, as the faster weapon with more DPS may significantly increase the amount of damage your signature spells are dealing while slightly reducing the damage your spenders are dealing. How significantly and how slightly, as well as how much of our damage really does come from signature spells, will make a big difference when it comes to weapon choices.
In any case, I doubt a build with no signature spell can be effective. "Playable at best" is my guess.
When I played Wiz during the open beta, it felt like you ran out of ap constantly and had to wait for it to recover. Imo Signature spells should grant ap innately, without needing runes, nor passives for it.
Even with all the running around, I find it hard to believe we'll run around so much 100% of the time to never really run out of AP. If we do, then Blizzard did a bad job. Even in the beta, where 2-3 arcane orbs pretty much clean house and then you're off running to the next pack that you start with full AP again, I found myself finishing monsters off with the signature spell because my AP was still regenerating. In other words, we'll probably run around a lot, yes, but probably not enough as to never run out of AP.
I agree with you, in that it should never be possible to completely ignore our resources. However I think that it should be possible to play without signature skill even on Inferno, but it should come at great cost. For example, you should have to focus on AP regen and AP extending passives and items to do this and even then you should play perfectly, meaning that if you miss one of your AO you'll get in trouble because you'll run out of AP and won't be able to do much until it regenerates.
I think if your build can run out of AP, then it needs a generator, and not much you can do to get away with it. I also don't see any effective builds that have a good chance to not run out of AP, even when you assume some decent amount of movement. If we ignore the free ROF rune (which is practically a signature skill), the only thing you might consider is one of the skills that cost 20 AP (like arcane orb with cost reduction rune), avoiding any other real AP-costing spells (so no skills like hydra, wave of force, teleport), getting a(some) AP generating passive(s) and using a very slow weapon.
The beta has maybe seen 1/10th of possible rare boss mods, nothing so far has had resource drain... although its likely that it will exist and will be prevalent in hell/inferno. I think the chances of you getting away without a resource generating skill while playing solo is unlikely, in a group however we might see lots of them, for all the ranged classes at least.