In terms of technology I think the big change at the moment is the gradual death of tape. Direct to Hardrive/flashcard/P2card is without doubt the future of production. The advantages of non-tape recording are huge, both in production and post production.
HD has done the damage to film I suspected and I think the days of SD are numbered - five years max.
However, I think all of this pales into insignificance in comparison with the advances in post production. I think where the most significant changes at the moment are all in post-production -- in particular 3D animation, CGI and effects. There are a lots of really interesting new developments in this arena and I expect to see the first truly "indie" animated feature film to hit the cinema by about 2010. I also think it will rock Hollywood to its core, simply because animation is about to get easy, fast and incredibly cheap.
My best guess is that this is where we'll see an explosion of single person content production.
In other arenas I think sometime in the next three years web based distribution will start to do to the DVD market what iTunes has done to CD sales.