They have two kinds of characters, Regular, and Main. You get 1 main and 3 regs per server, your regular characters are limited to 70% max skill in any skill line, but they can re spawn when ever they die and work just like any other MMO's characters for the most part. Your Main on the other hand, can hit 100% max skill, can create guilds, and most importantly, is susceptible to Permadeath. Yes, your Main character can die for real. There are some catches to that. Mains have longer 'bleeding out' times. Mains also have the possibility of '2nd chances' where there is a slim possibility that your toon will be saved (whether by local NPCs who drag you to a healer, or by the Gnolls that are taking you back to their cave for a later meal). It also sounds like Mains will have the possibility to effect the world and story line more so then regulars.
This game has everything I was hoping for with one exception. The PvP aspect doesn't sound like it is RvR styled. It sounds much more anything goes shadowbane ish, where anyone can kill anyone. The developers had lots of tricks up their selves to make killing mains much more challenging (only a Main can kill another Main, and all Main avatars look just like regular avatars, and since there are no levels, there is no way to check the 'con' of another player). So it should be pretty intense.
Any ways, it looks like a fun one to keep an eye on.