Blu Ray will be around for a long time but if it gets wacked by something it will be this and not downloads. With a maximum storage of 3.9 Terabytes it will probably allow for uncompressed video, as well as uncompressed audio. With HVD it will be like going to the local cinema in terms of potential quality, although only a small number would actually be able to take advantage of the quality do to the financial resources you would have to invest in a home theater to get the actual quality availible on the discs.
Oh god should I stop buying Blu Rays now so I can start on my HVD collection. If by chance HVD becomes available to the average consumer I will be so damn old I will have coke bottle glasses and will have my hearing aid turned up to 11. For the next 15-20 years or so I will be blissfully enjoying my
Blu Ray's!