It can almost be guaranteed that over the next 5-10 years we will see a full transformation of the ski dvd industry go stritly online and digital. A few companies are already doing some interesting things with online downloads, so expect things to be pretty much 100% digital - no more dvd's.
This transformation can already been seen with certain video streaming mediums such as Netflix which has streaming both to xbox 360 and ps3. So inevitably i see some very interesting marketing techniques coming out to enhance the "downloadable-lifestyle".
Pirating is definitely a BIG issue when it comes to ski DVD's. I know of certain people that have even started groups, selling pirated copies. Although not very big time, every single copy not bought is a copy dollars not put in the company that broke their back producing the film. And that can turn out into quite a marginal loss if you are looking at revenue stream in the long-run, though not so much in the short run.
A ski movie is a fairly minimal purchase, from my perspective at least, in terms of value to monetary loss from a consumer standpoint, so i don't think the poor economy really had a "big" effect, although factors stemming from the hype of the falling economy certainly did impact film sales.
Get ready for the change in distrubution - get your marketing caps, and although sales for DVD may be seen as falling currently, the new surge in distribution will give a never before seen audience a chance to purchase movies.