If y'all are curious about the Skill Tree, here's the rub from my 4 hours with the game: Noctis has 29 skills. They're generally speaking not 'all new skills' as you might be used to from a Crystarium or Sphere Grid, but are instead things that adjust the way Noctis plays. Several skills for instance are reserved for chain attacks - when you start, Noctis can't naturally chain together attacks with anything other than a standard sword. If you want to chain attacks together with a polearm, that's a skill you can buy. Want to chain attacks with the big greatsword? Pick up the "Greatsword Link" ability, etc.
There's also skills that let you do things like "Airstep" (take a step in mid-air after attacking) and "Blink" (dodge forever without consuming any MP) - things like that. I didn't look at the skill list absolutely extensively, but the only thing I remember being a more traditional FF skill on the skill tree is Libra, which is an early-game skill that makes the strengths and weaknesses of enemies show up when you lock on to them.
Basically, this feels a little more like, say, the combat skill tree (but not the other trees) of The Witcher 3 rather than a traditional FF skill tree.
Each of the guys has a similar skill tree, though theirs seem a little smaller than Noct's (but I didn't count theirs, unlike his). These skill sets basically are a way for you to direct them down a path... so, for instance, you can make Ignis more focused on healing by getting him the healing-focused abilities, things like that.
I'm not sure if this is the 'final' number of abilities, but I will point one thing out: some fans have theorised more will unlock because Noctis' skill tree only fills one bit of the circle. When you see the design of the screen this makes more sense though: Noct fills up the bottom of the circle, Prompto the left side, Gladio the top, Ignis the right, so when you look at them as a whole, as a group, their skills fill the complete circle. Who knows if there's a secret hidden away that'll unlock more abilities for Noct when he puts on the ring though. (But if I had to guess, the ring stuff will probably relate more to summons and phantom weapons and not to the skill tree - just theorising on my part there).
Each of the characters also have a unique character level for their skill... cooking for Ignis, Photos for Prompto, etc. I'm not sure how this impacts how they use these abilities though, other than the obvious factor that as Ignis levels up the meals he can make you will get more impressive. No doubt this has been talked about in Famitsu or something & I'm just clueless on it tho.
Oh, and, AP -- it's a shared pool. So you earn AP as a group and spend it. This means if you want you can ignore your team and pour all your unlocked AP into abilities for Noctis, but then your party will be weaker. Skills don't cost just 1 AP, but vary in cost depending on how powerful they are.
In my interview with Tabata at Gamescom (which SHOULD go up tomorrow), he explained that the main choice with the skill tree is between if you want to play the game like an action game or want more assistance to make it a little more slow/tactical like an older FF. That's really abridged, but you can read his response in full for yourself soon enough...
There y'go. Saved you all some time!