I really like the idea, and would definitely be interested, but to be honest, I probably wouldn't be willing to pay. Maybe an ad supported version, and you can pay to remove the ads or something? It would be nice to be able to take a quick glance at a trail, and see what it looks like.

It does look like google has started to do this:

http://blog.cheaptents.com/street-view-google-sherpa-cam/