Can't wait.
I'm glad Storm of Swords will be split between two seasons, some of Season 2 (Clash of Kings) felt rushed, like Arya'a time on the run from King's Landing/time at Harrenhal, or was skipped over entirely, like Theon and Reek, while other shit was done horribly wrong, like the "Where are my Dragons?!?!?!?!" plotline and their atrocious version of the House of the Undying.
While the third may simply be an unforgivable matter of poor script writing (possibly due the the fact that the House of the Undying in the books would literally spoil the series if we were able to visually determine who was who, and they therefore had to rework the entire sequence), the first two were a simple matter of time constraints. Clash of Kings really should have been two seasons as well, it would have given Martin more time to finish the series before the show catches up to him as well.
As I understand it, he is about 400 (manuscript) pages into The Winds of Winter, so, assuming this is true and the publishers decide this time to not give him shit for coming out with a 1500 page behemoth, we might be seeing Winds of Winter and Dream of Spring a lot sooner than we saw Feast for Crows and Dance with Dragons.