I'm considering getting back in the saddle, and probably going sport/standard bike this time.  What's the state of the art when it comes to helmets, jackets, and gloves these days?  Any jackets for hot weather that are worth a damn if you go down?  I've seen all sorts of perforated materials, but do they hold up against the pavement?

From what I've seen in the past when it comes to FF helmets you pay for the comfort and air circulation.  What's a good one with a good airflow?

Pleanty of pro-racers wear perforated leather suits when racing in warm/hot weather. If they're prepared to trust them, I don't see why you and I can't (depending on the quality of the leather and stitching). There are also synthetics that allow reasonable airflow through the fabric without needing perforation holes like leather does. I've had a couple of minor low speed tumbles while wearing a synthetic jacket and apart from the fabric being scuffed the jacket held up fine. I haven't had any sort of high speed tumble though.

As for helmets, I've only ever bought Shoei helmets. My current one is an RF-1000 (Voltage TC-1 colour scheme) I bought 2 months ago and I like it just fine, but it's winter here in Australia right now so I can't say how good the venting is in hot weather. I can't say if other brands are better or worse.

Depending on how much high speed riding you do, helmets with lots of vents sticking up on the shell can create more wind noise. Also look at padding around the ears. My new helmet has less padding in that area than the previous one and I can hear the wind noise a lot more clearly than before. For long trips I'll probably get some earplugs to avoid abusing my eardrums too much in the new helmet.

Snell certified helmet (although thats been up for debate these days).  Leather is always good, textile's do actually hold up decently in a accident, but its still not leather.  Perforated will keep you cool enough, and should protect you just about as well as any non-perforated leather.