A battery breakthrough by Stanford researchers, with a possible several-fold increase in energy density:

http://www.gm-volt.com/2007/12/21/gm-voltcom-interview-with-dr-cui-inven...

Over the years, I have seen at least 100 announcements like that.

Little Hope for the Just-in-Time Technology Fairy,

Alan

I'll second that - if half of the fantastic announcements we saw had come true I'd be writing this from the promenade deck of a cruise ship ... docked at the Martian moon of Phobos, awaiting my shuttle to the surface .

At least they have a working prototype of it.

I don't really think your post is the best response Alan, although I certainly know where you are coming from!
Ballard comes to mind, with their technology for fuel cells in cars, of which many of us had high hopes and it came to nought.
We have to accept that cutting-edge technology is high risk, and that most initiatives do not work out.
If we allow prior judgement to cloud our thinking we will miss out on the one in a hundred which does work - and it is that one which makes all the difference.
This is hardly a 'wow, if not for this coming along, we would be screwed' technology anyway.
Battery technology already to hand can make a substantial difference, and improvements are moving along on a broad front, so we are not dependent on one particular breakthrough.
To give a couple of examples, neither Toyota nor Caterpiller are known as unrealistic dreamers, basing their successes on solid engineering, and both have new technologies in the works, in Toyota's case they are confident enough now of the reliability of Lithium Ion technology to announce that they are going to be using it in cars, and in Caterpillers case with their Firefly improved lead acid technology.
This silica nanotechnology will be great if it works commercially, but it is not the only game in town for improvements, and there are plenty of others who are looking at improving anodes and cathodes.
I haven't come across anything with so many scams as renewables and advanced energy systems though since I was offered a deal on the Brooklyn Bridge!