The "plastic" brain? Studies in neuroplasticity

Anyone else catch the PBS "Brain Fitness Program" over the weekend? I think they're playing it all through December, depending on the region. There were a number of fascinating talking heads: Dr. Norman Doidge, Sharon Begley, and Dr. Michael Merzenich. Seems like we've made a number of breakthroughs towards harnessing the potential of the human brain and using neuroplasticity to maintain cognition and quality of life as we age, no small achievement. During the pledge break, PBS was actually offering a brain fitness software program, courtesy of Dr. Merzenich’s Posit Science company, for people who donated enough money.

Can anyone comment further on these kinds of programs? Is neuroplasticity a burgeoning field?