Reincarnation just requires a new state to be added for when a player dies, they die as usual, you fire off make_corpse() and all the rest of it to shift equip and stuff about and then don't let them get moved out of the room thier corpse is in (unless you want them elsewhere) and just tag them with a flag of some sort to indicate thier now "dead" status. Once like this a skill doing usual % checks and stuff to remove the flag and thus restore who they are.
In essence that is what you want, which is rather minor modifications, if that is what you want I can be more specific as in where and what needs tweaking.
Only one other thing, while "dead" how do they differ from a "live" character? Dead people, for lack of a better word lets call them Ghosts, have this thing about not being able to physically interact with material reality (unless they are able to force enough willpower to create mass.. but thats up to you) which means all the interaction code needs to check for this "dead" state. Also can everyone see Ghosts? Is it skill based? etc, etc..
Samson and I had talked over something like this a few months back (*wonders if Samson can remeber that * ) about having players die, turn into Ghosts then have abilities like posession and limited abilities to interact with the physical world based on this and that.. it could be taken in lots of directions. Then there would be a reincarnation center to bring yourself back to life, others could rebind you to your body etc.. I dunno if Samson start, or finished up system design on that. But it is quite a feasible implementation.