Of the public schools I have worked in, in two states, their video libraries consisted of 90% VHS tapes.
Some valuable teaching tools (videos) are going to be really difficult to find on DVD, and a lot of them just won't be found.
I am not saying VHS should stick around, but as the format dies there will be a somewhat substantial loss.
I don't want to write an epic rely here, but you really ought to go into older high school's libraries to see what I'm talking about. Even if they have the tapes (which wear out eventually), not having VHS players that work is going to be an issue.