I'm on Al Gore's radar – for showing a path forward

It is important to realize that there are two very different topics being mixed when folks talk about “Thorium Reactors”. One is a “Molten Salt Reactor” and the other is using Thorium as fuel.
The two are separate.
They only get mixed if you want them to be mixed.
http://chiefio.wordpress.com/2011/04/12/nuclear-reactor-types/
So we can run Thorium, now, in our existing reactors if we wished. A small company has worked out the fuel pins to do it. Also, as noted above, the CANDU reactor works on Thorium, as does the Indian “knock off” of the CANDU.
You can even run mixed fuel beds of Thorium and Uranium and MOX (Pu / U )
So we can start the whole “develop a thorium fuel infrastructure” process now, if we wanted to do so. Mining (by product “waste” of “rare earth mining” at present) and fuel fabrication. Certification trials, etc. Then, whenever desired or complete, start running MSR types with Thorium in them.
We’ve already made Thorium “go”.

BORAX-IV, built in 1956, explored the thorium fuel cycle and uranium-233 fuel with a power of 20 MW thermal. This experiment utilized fuel plates that were purposely full of defects in order to explore long-term plant operation with damaged fuel plates

Note that U-233 is what is produced from Th when it gets irradiated.

I must lead this section with my favorite reactor design. The CANDU. This Canadian design is, IMHO, just stellar. The US designs of the era are compromised by the US Government’s demand for ever more proliferation resistance, even if that meant kludgy designs The CANDU was made to use natural uranium (so no first step enrichment needed to be in the nuclear business) and have active refueling while on line (so easier and in many ways safer operation as the whole core does not need to be shut down and opened). It is also flexible enough in the use of moderator and absorber plates that the fuel used is highly flexible. From U to MOX (mixed oxide with U and Pu) to Thorium.

Fuel cycles the CANDU can use (nice drawing):
http://upload.wikimedia.org/wikipedia/commons/f/fe/CANDU_fuel_cycles.jpg
This Indian reactor uses U-233 metal bred from Thorium in other reactors.

KAMINI (Kalpakkam Mini reactor) is a research reactor at Indira Gandhi Center for Atomic Research in Kalpakkam, India. Its first criticality was on October 29, 1996. It produces 30 kW of thermal energy at full power.
KAMINI is light water cooled and moderated, and fueled with uranium-233 metal produced by the irradiation of thorium in other reactors.

So there are several and sundry ways of using Thorium even in our present reactor fleet.
As a distinct issue, there are Molten Salt Reactors that may use Thorium, or can use other fuels.
Oh, and we can use MSR to get “process heat” for turning coal (or trash or…) into Diesel fuels and gasoline if we so desired:

There are also the Very High Temperature Reactors that have an outlet temp of up to 1000 C and are the reactor I usually talk about in the context of making nuclear “process heat” for cheap “Coal To Liquids” facilities.
http://en.wikipedia.org/wiki/Very_high_temperature_reactor
That includes a liquid salt cooled variation as well, the LS-HTGCR

The molten salt cooled variant, the LS-VHTR, similar to the advanced high temperature reactor (AHTR) design, uses a liquid fluoride salt for cooling in a pebble core. It shares many features with a standard VHTR design, but uses molten salt as a coolant instead of helium. The pebble fuel floats in the salt, and thus pebbles are injected into the coolant flow to be carried to the bottom of the pebble bed, and are removed from the top of the bed for recirculation. The LS-VHTR has many attractive features, including: the ability to work at high temperatures (the boiling point of most molten salts being considered are >1,400°C), low pressure operation, high power density, better electric conversion efficiency than a helium-cooled VHTR operating at similar conditions, passive safety systems, and better retention of fission products in case an accident occurred.

Note that this does NOT say “Thorium”. It can be, or it can be other fuels.
The simple fact is that we can use Thorium any time we want and we can proceed with MSR design and testing any time we want and we can mix those two, or not.
I looked at some of the more recent efforts here:
http://chiefio.wordpress.com/2013/01/08/thorium-china-india-piigs-demographics/
that shows how various countries and consortia are shifting positions. (Along with looking at some demographic connections).
So we have made “MSR” in the past. We can make them again. We have used Thorium fuel in the past, it is being used now in India (as they have lots of Thorium).
It just isn’t all that much of a Brave New World so much as knocking the dust off the old world and sprucing it up some. In fact, the first full scale commercial reactor used it:
https://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Station

The Shippingport Atomic Power Station was the world’s first full-scale atomic electric power plant devoted exclusively to peacetime uses.[notes 1][notes 2][2] It was located near the present-day Beaver Valley Nuclear Generating Station on the Ohio River in Beaver County, Pennsylvania, USA, about 25 miles (40 km) from Pittsburgh.
The reactor reached criticality on December 2, 1957, and remained in operation until October 1982. The first electrical power was produced on December 18, 1957 as engineers synchronized the plant with the distribution grid of Duquesne Light Company.
Shippingport was created and operated under the auspices of Admiral Hyman G. Rickover, whose authority included a substantial role within the U.S. Atomic Energy Commission (AEC). Its design team was headed by Alvin Radkowsky.
Its final core was an experimental, light water moderated, thermal breeder reactor and is notable for its ability to transmute (inexpensive) Thorium 232 to Uranium 233 (the latter being the fissile material that fueled the reaction within the reactor core). The reactor was capable of an output of 60 MWe. The reactor was designed with two uses in mind: for powering military ships, and serving as a prototype for commercial electrical power generation. In 1977, it was converted to a Pressurized Light-Water Breeder Reactor (PLWBR). Over its 25-year life, the power plant operated for about 80,324 hours, producing about 7.4 billion kilowatt hours of electricity.

So many folks have already consumed electricity from Thorium.