Not really certain I'd want "good" AI in a Souls game. Player characters are relatively low-capability, so having AI that smartly coordinates attacks, punishes you during recovery frames with quick attacks, or plays really good rushdown game would greatly limit the player's options in combat. It would also, in all likelihood, encourage cheese tactics like kiting/sniping or terrain exploits even more than the game does already. Situations that already exist in DkS2, like enemies mixing up delays/extensions in their combo strings, can feel a little cheap as is...not certain how smarter enemies would work out in general.
I wouldn't mind seeing more one-on-one boss fights with better scripting, though. Few worries of cheap attack-stacking there. Something like the better NG+ Black Phantoms or the Crushed Eye Orb fight would be great. Take those as templates, remove the ability to chain-stun or backstab them, and the skeleton of a very satisfying boss fight starts to form. Flesh it out with some fluff and art design and you've got a real memorable foe. But methinks From would see fights like this treading a bit too much on the Old Monk/Looking Glass Squire design space.
Now for some more PvP (and PvE) highlights/lowlights. Ditched my Dex/Pyro shitcharacter almost entirely, and have been rolling with my Strength/Faith build.
-Thorned Greatsword is excellent. Actually dealing appreciable damage to enemies and opponents is really fun, compared to piddling damage with whatever shitastic Curved Sword or Spear I used in my other character. Also helps that I have access to the wonders of weapon buffs, namely Sunlight Blade. Can shred bosses and enemy phantom's quite quickly, even in NG+. Defender Greatsword is pretty nifty too. The built-in buff and higher proportion of lightning damage can be pretty useful. Unfortunately, yI lose out on that sweet lightning bolt special attack. Smelter Sword can even be pretty fun to use and I'm even experimenting with all sorts of Lances. Strength builds seem to have so many decent weapons...hard to really pick which one to play with.
-I really like backstep/roll cancels. For those not in the know, the windup animation of most spells and attacks can be canceled into a roll or backstep. Not terribly useful for PvE, but outstanding for PvP mindgames. Throw out a Lightning Spear or two that the opponent will likely dodge with ease and make them think you are some sort of newbie. When you throw out another one and they try to punish during the windup, backstep cancel out of it and immediately attack. The Claymore/Defenders/Thorned sweep attack works wonders at catching opponents unaware. The downside is that this sort of cancel costs a decent amount of stamina to do. But employed well, it will really help up your PvP game.
-Low stamina regen really makes paying attention to what you and your opponents use for moves important. It punishes spam of any sort, as a good opponent will know when you are out of stamina and punish appropriately. Really interesting.
-The guard-break move is excellent at snagging turtlers. It's also great to bait out and punish. Pretend to turtle, bait the guard-break from an unsuspecting opponent, drop guard and immediately punish. It's poor against extremely high-poise opponents (like everybody and their brother wearing full Havel's on NG+), as they will often tank the hit while still stunning you with the guard-break, but it works well enough elsewise.
-Some rings are dumb. Old Sun Ring is still dumb, Ring of Thorns +2 is extremely stupid, and Gower's Ring is it's own kind of silly. The only type of counter-attack ring I could really tolerate is something that had a chance of casting the equivalent of Force on hit. This way it serves a function of reducing the chance of stunlock, but it also doesn't randomly kill opponents because of latency.
Gower's Ring is just plain silly, though. It prevents all damage taken from behind. It can prevent 4-5 hits generally, with 6-8 hits stopped when the wearer dons a Bracing Knuckle Ring +2. I don't really know if this is overpowered, but it creates some absolutely dumb gameplay where an opponent puts their front against a wall, chugs Estus, spams Repair Powder, and essentially gains a free reset. There's a lot of moving parts here (the 10 equip burden, for a ring, is nothing to sneeze at), so this might not become Second Chance v2.0, but I think this bad boy is something to watch.
-Really beginning to hate the Major League Gaming Sword. Yeah, yeah, Rebels/Watcher/Magic Sheild is tech, but the thing completely warps the meta. A damage nerf would be nice, but I'd settle for it not being infusable/buffable. That's just too much.
-Bat Staff is also annoying. Getting Dark Fog ganked on summon pretty much has killed my desire to use the RSS (woo-hoo, no healing items allowed!) in NG+ anywhere I think there may be Hexers (i.e. practically everywhere). Also hilarious how much better Hexers are at dishing out poison than dedicated Dex builds are.
-Soul Memory and arena matchmaking still blow. Bluebro arena is worthless given the cost of entry, given the high propensity to be matched up with some SL828 Havel's hexer powerstancing Demon Great Hammers buffed with Resonant Weapon. Yes...that happened. Yeah, I'm salty as fukkkkkkkkkkkkkk. Great job, From! In trying to prevent newbies from being trolled by twinks, you made everyone else suffer through horrible matchmaking. I'm pretty certain the Way of Blue covenant would have sufficed to keep newbies safe from twinking reds (doesn't also hurt that it's much easier to become a Bloodbro than a Darkwraith, meaning red invaders aren't self-selected to be "better" players on average). And it would have made wearing the Sentinel Ring maybe work once. Probably wore it for 30 hours, while human, over two characters at all sorts of times/places/SLs/SMs and not a single summon.
-Fuckin' salamanders, man. Fuse one of these bad boys with one of the Mace Drakekeepers, give it the ability to cast Profound Still, and now you have a worthy final boss fight instead of the absolutely pitiful one we got.