this is an awesome thread---feynman, humanino, fredrick, and others have said some profound and/or witty ideas
I will try to join in, but am admittedly not quite up to philosophical speed.
Anyway, i think that human thought goes in expansion contraction waves and it is just getting a new concept of time and space
the last time like this was around 1680 when Newton postulated absolute space and time. after that the program was to explain everything by particles moving in that absolute space according to some laws, and by waves moving in it. the program developed enormous momentum.
heat and sound were explained by particles moving in abs. space
electricity and magnetism, light, even quantum field theory and the Standard Model are built on absolute space and an idealized time variable
A crack developed in 1915 with Gen Rel in which spacetime points do not have physical existence, there is no fixed geometry. In GR there is no absolute space, there is just the gravitational field. but the rest of 20th cent physics will not mix with 1915 GR---it is like oil and water.
So I guess something like 1680 will happen. People will get a new model of time and space compatible with Gen Rel. then they will build quantum physics on the new spacetime. there will be a new program.
The program is always one of unification----of gathering the threads of explanation together---of braiding the threads of understanding. But be careful what you unify in with!
It is a different program depending on what the core concept of space and time is!
Actually the phrase "Theory of Everything" sounds a bit presumptious to me. I would be real happy if people could just come up with a quantum theory of spacetime and matter-----I would not call that "Everything". Just a modest theory of how space behaves, how and why matter curves it, a quantum theory of space at the fundamental scale, and just a modest quantum theory of some matter-fields living on that quantized space. Never mind consciousness or life or other grand topics. Just modeling a room inhabited by some matter would be great!
But we don't have that. 1915 Gen Rel invalidated both Newton's absolute spacetime and the minor variant of it that came with 1905 Special Relativity. I don't think we have the new one yet.
So I don't think saying the phrase "Theory of Everything" means anything.
We have to let history unfold. Whatever we picture now will be mostly wrong. I personally feel sure that the new historical wave will begin with a quantum theory of spacetime, that is to say a quantum theory of the geometry of spacetime (which is the gravitational field). there are half a dozen good approaches being worked on---maybe one of them will pan out.
the moment we have such a theory---then something like Newtons's 3 laws will happen, and a new program will start, and wave on wave of unification----putting things together within the new context.
personally, the most evocative thing I have heard along these lines recently is a talk by Ashtekar (with slides) that is downloadable. The whole talk lasts 1hour 16 minutes
He was talking about the gravitational field interchanging with matter, how a black hole evaporates----not just the semiclassical way hawking says but the way Ashtekar says. He was talking about the deep Planck regime at the pit of the hole too. the good part starts around minute 34, and then it gets even better at about minute 56 (out of total 76 minutes as I said)
this is what, to me, sounds most like the beginnings of a theory of time space and matter.
I will get link for it, incase anyone wants. Stingray, who is at Penn State, supplied it
Stingray said:
Ashtekar recently gave a talk where he discusses this a bit:
http://www.phys.psu.edu/events/index.html?event_id=934;event_type_ids=7;span=2004-08-20.2004-12-25
Hopefully that's a static link.