Batteries have been improving at a rapid pace already:
Considering the amount of research going in to advanced Li-Ion and other promising technologies, I wouldn't count on that trend stopping or slowing down. The opposite, actually.
There have been incremental improvements over the past 25 years but the true breakthroughs have been few and they’ve come from a small group of researches. OTOH, articles about breakthroughs that don’t amount to anything grow on trees, and I’d still like to have a dollar for every one.