@croydon - I think it depends on how it is used. If you've got really dry skin and you only put the Vaseline on it for a little while then remove it, I think that can really help. It traps the moisture in your skin so that it can heal.
I have a friend who gets really rough skin on his elbows and knees and he uses Vaseline without any issues.
I don't really think it's a good idea to use it for things like eyelashes though, simply because I think it grows bacteria really easily, so any Vaseline you put near your eyes (or most things that get put near the eyes for that matter) can be a risk of eye infection.