I haven't played the beta, but I've played with the skill calculator on the website and a lot of the options look like they provide customization. Even if the customization is on the same level as D2, I will be excited since the PVP there was amazingly fun. I did not play typical builds either and rarely lost on my plague/lighting javazon or my fire sorc (even destroyed on FW/hydra sorc before FW got nerfed).
@ Grignard - Just curious - why are you comparing D3 to other MMOs? I can understand comparing GW2 or WoW to other MMOs... but D3 is really not an MMO. It's an iso dungeon crawler RPG that happens to have multiplayer and PvP, but you're not thrown in a huge open world with hundreds of people standing around.
In the same genre, other games have far more customization. Torchlight is one, it's successor is another. D3's predecessor is another. Hell, Sacred 2 was a horrible game in the same vein (iso dungeon crawler RPG), but it had more customization than D3 does.