I guess nothing.
I don't believe in a soul or in the afterlife.
But I do think that in the future it may be possible to map out a persons brain(thought pattern etc), record memories & copy them to another medium. Technically it won't be the same person, just a sentient, artificial replica of the, lets say, for a lack of a better word, consciousness the person.
Personally, I think that when you die, you just cease to exist. And I don't have any problem with that (I sure won't when my time to go has gone). I don't think that our being stretches beyond our lifespan.
However, I do think that people live on in their friends' and family's memories, allowing them some kind of heaven (mainly the good stuff is remembered).
That's not to say that I use that as an alternative to heaven based on my Christian roots. But I do like the idea that I will be remembered for at least some time after my death (again, not that it would matter to me once I'm dead).
As for taking solace in the idea of people passing on the heaven, I don't need that. My emotional system doesn't work that way I guess. Then again, I haven't yet encountered a death closer than my grandmother passing away, and we saw that one coming a long time ahead.
I guess it eventually comes down to how people deal with the emotion of losing a loved one, and a lot of people take solace in the idea of considering the one passing away as going on a journey, at the end of which they meet again.
I've managed to find contentment in not knowing what comes next. Sometimes I find that I'm very excited and curious about it.
I know what I hope happens, and that basically consists of becoming energy and existing in that form somewhere in the cosmos, I suppose. I know that I wish it were possible to be aware of everyone and everything; to be connected to everything. That's just what I hope for. :)
There was another thread on here in which someone said, "I view death as a return to the state I was in before I was born." That's probably the best description I've ever heard, but I have to add something to that.
If "you" were in some sort of state of nothingness BEFORE you were born, and then you eventually return to that state, is there anything that would preclude the possibility that "you" could arise once again out of that state of nothingness? How do you know this hasn't been the case forever and ever, for both yourself and the universe(s) as a whole? We know that memory can be extinguished, but is it actually possible for awareness itself to be extinguished? It seems to me that it is impossible to "experience" nothingness because nothingness isn't even blackness (which is an experience); it is a complete lack of experience, which is impossible to experience. The fact that you are aware right now, experiencing something right now, could mean that (relative to your perspective) you will always seem to be aware of SOMETHING in the present moment, whether that awareness is as focused as a wakeful, living, intelligent being, or "muted" similar to what you experience when you are asleep and not dreaming. Science assumes that matter is unconscious. Do we really know this to be this case?
Physicists seem to think that time may not exist in the way we think it does. Could it be that some sort of "reincarnation" could occur in a manner that is unbounded by time?
I don't believe in a "soul" in any traditional sense of the word. I know that when I die it will truly be the death of me, if we define "me" to be my thoughts, memories, personality, body, etc. etc. These will be extinguished. But it seems to me that the awareness that I am, that is currently experiencing this body's thoughts, memories, sensations, etc. cannot be touched. If there is anything like a soul (ick, I still don't like that word), we are probably all different manifestations of it, experiencing itself from different perspectives. I've heard it referred to as the "void" from which we all arise. It is not a god, it is a void.
This is not wishful thinking on my part. I would rather live forever in a pie-in-the-sky heaven or simply have an end to all the suffering of this life. Life is full of suffering and struggle. I don't want to live forever that way.
I think that this xkcd comic puts a neat perspective to that.
I don't think I 'was' before I was born or that I 'will be' after I died. The configuration that 'is' me and is the accumulation of my body, my memories and my thoughts will cease to function and start to deteriorate and the 'me' will be the thirst thing that is gone, never to return since any 'gap' of nothingness cannot be overcome (just like life in general; one interruption and it has to start all over again).
Reading this back for myself, I realize that this may sound a bit morbid, but I do like to view things as they are.
That's a great xkcd. It's really kind of a pointer to the fact that "you" are nothing more than just a concept. "You" don't really exist concretely, "you" only exist in the abstract. So only the CONCEPT of you can cease to exist...