It would be awesome to see most of these "concepts" become reality in the next little while, although considering what Big Business the disposable-battery industry still is, I am not hopeful. "Rechargeable Alkalines" were developed in the 1950s -- well before Alkalines were even available to the average consumer!
http://technologyinnovationsite.com/battery-concepts
There are definitely some cool ideas there.
For most AA and AAA applications, I buy Energizer NiMH batteries. They store lotsa juice and can be recharged hundreds of times - the only downside is they drain quicker than throwaway alkalines. In today's high-tech high-power gadgets, that's not such a big deal, but we shouldn't use them in, say, a smoke detector. Oh, they also cost five bucks for two, so the initial cost is way higher.
We used to use the C and D sizes of the Energizer NiMH but those were really light and didn't seem to have any power to them. Especially the Ds.