There's a nice article in The Atlantic this month by David Gary about Yale's VHS preservation initiative, which has been focused on saving horror and exploitation titles on VHS. There's no doubt that the VHS wave has a great deal of historical interest - with some videotapes selling for hundreds of dollars on collectors' markets - and that many of the films that were released on VHS have never made it to any subsequent video platform (the article's author cites an estimated figure of 40 to 45%).
For any who see this as a futile exercise and an example of unfortunate institutional hoarding, bear in mind that many of the films that are now lost - films we would today see as historically and artistically important - were discarded years ago because they were seen as low-cultural trash. Scholars today would kill for a print of the Tod Browning/Lon Chaney silent LONDON AFTER MIDNIGHT, but it was not considered a worthy enough candidate for preservation when there was still time. Future cultural archaeologists may well find more of value in NAIL GUN MASSACRE than they find in the entire filmography of, say, David O. Russell.
Here, is Yale's own guide to the collection.