It's not really surprising that the 787 has had problems with its batteries. Anyone flying model aircraft over the past decade might have predicted it. What is surprising is that there are now newer safer lithium batteries that modellers use, that apparently weren't chosen for the 787 because they were too new to certify...
Anyway, another development in 'battery' technology:
http://www.phinergy.com/default.asp?catid={E0C0EE82-1E6A-44B2-9F72-6A4E77ACE1C4}
This one is interesting in that it would give plenty of range for an electric aircraft. Perhaps it could be used in combination with a rechargeable battery so that you could enjoy an hour's flight (currently possible) but still have good reserves.