Conveniently enough, he called me tonight to compare notes on our Thanksgivings, and I got a plain-English explanation out of him that I can still remember at the moment.  What I wrote above was garbage, here's a better overview of the process and the problems:

Both teams arrived at the process of creating stem cells by observing how it's done naturally--that is, how a developing female embryo can create egg cells (which grow into anything) out of existing cells that have already been specialized.  In mice, it was found that by taking cells from connective tissue, then activating four special genes inside the cell via retrovirus, the sampled cells would stop acting like connective tissue and start acting like stem cells.  This was verified by implanting batches of the cells into nude mice and letting tumors grow--only stem cell tumors differentiate themselves into teratomas, so the presence of these tumors was a positive indicator that the researchers were on the right track.

The next step was to see if the same process used on mouse cells would also work on human cells, and sure enough, it does, hence the press releases.  Yay science!  But here is the catch:  One of the genes that needs to be turned on to make this work is a known protooncogene--that is, encouraging c-Myc to express itself inside a body is a quick way to get that body to grow tumors.  So prospective treatments will have to ensure that the elements used to generate the stem cells are not introduced to the host body.

(is 3fingerspointback)

I see the big problem with stem cells is that non-scientists lose the point almost immediately and veer off into discussing science fiction scenarios with wacky ethical 'gotchas!'.  

Q: "What if I stick a cloned replacement brain in my sons accidentally de-brained body? - will God be ANGRY?!"
A: The Lord giveth and the Lord de-braineth but then the Lord provideth a new empty brain which surely proveth the Lord is a fucking crazy enigma and that's how HE roll-eth.

Dude, seriously?

Q: "What part is the part that makes us human?"
A: YOU = (your physical parts + your life experiences) * intelligence / (what you've learned +/- how much you've had to drink) * your 'top shelf' repertoire of habitual responses

...Or make your own equation - I tend to believe that without our memories(or our original factory installed brain) there really wouldn't be much of a 'self' present. If you open the case and start popping aftermarket brains in there - you've voided your self-hood warranty.  They should have that disclaimer before each episode of 'PIMP MY BRAIN' on future television.

I love a good science fiction story with creepy visualizations of the protagonist discovering a warehouse full of brainless clone bodies floating in tanks of glowing liquid and then hitting the audience over the head with some sort of 'this is SO WRONG! (and its gross!)' moment.  The problem is that THIS real life stem cell story is nowhere near that cinematic level of emotional payoff for the audience.

What this story seems to say is that some scientists have been able to flip a few genetic switches in mouse skin cells and they turned into Teratomas (read that wiki linked above - these teratomas are a FAR cry from cloned brains, organs, or a satisfying backdrop for heavy handed movie moralizing.).  The scientists were able to flip the same switches in some human cells with the same result  - so great, they can now induce freaky tumors at will - hooray.  

The real story here is how any stem cell news becomes a political football for the religious right to jerk its anti-abortion knees violently.  Some right wing hand waver will undoubtedly point to a press release about this story and start screeching about how they have been justified all along in equating stem cells with abortion and they don't have to feel the sting of any criticism for efforts to block promising stem cell research that might have helped actual living sick people sooner rather than later - you can be a tunnel visioned anti-abortion zealot voter without any moral qualms since non-fetal mouse tumors can be induced in a lab - yay!  The real story here is that politicians will exploit it in order to kill funding for medical research into fetal stem cells, as they have already been doing for years, and use this 'GREAT NEWS: we have discovered a way to give people tumors with eyeballs and teeth!' advancement as a red herring.

"...when theft and high crime becomes obscenely obvious to even the blindest beer sucking idiot, it is always the Republicans who are in office." -- Joe Bageant

I agree that this is exciting stuff...but I won't get too worked up until I can watch a new heart grow from a sliver of my fingernail on a boring Sunday afternoon.  Now THAT would be something.

It's the end of the world as we know it, and I feel fine