The Guild wars site has a newly-added Nightfall product page with the obvious content, as well as a the first in a series of Skills features:

Over the course of the next three days, we will be publishing an expanding page in our Guild Wars Nightfall section that provides insight into certain new skills, with a few developer comments about their potential uses and combinations. The Guild Wars Nightfall Skills Page today provides information about Mesmer, Paragon, and Dervish skills. Check back tomorrow for more skill info!