No short and easy answers on these questions. Lot of industry analysts would pay dear to know the answers right now. A lady with a crystal ball would be more helpful :-))
But jokes apart, you are mentionning too many dissimilar technologies, so I can give you just a few thoughts:
Microsoft is pushing
VB .NET (and other .NET technologies) very hard, and experience teaches us that when MS is pushing something, it means that the thing will be around for quite a while. So, Microsoft technologies look like a sure bet.
On the other hand, Linux/Unix and related technologies are emerging the more and more as a viable alternative to Microsoft products. I recently read and translated two books about PHP and liked the thing so much that it made me change my general opinion about Open Source software.
VRML is today just a curiosity, but so was XML once. Who knows, maybe in the next year or two somebody may come up with some technological breakthrough which coupled with VRML would produce the ultimate solution for all our database problems. But the probability is thin, so I would rule out VRML.