I agree with chiph.
Aside from that, the typical code monkey doesn't really grok their development language anyhow. Just give them enough basic exposure to the "rules of the road" and then have them "shotgun compile" a bunch of programs until they get the feel of things.
Sad but true, many experienced coders learn to program a lot like others learn to drive around their town. Ask them a question about where something is and they can't give you a location description that makes sense when you read a map. They just know "you drive down here, turn left, go about this far until you see the WalMart, turn left on whatever that next street is called until you pass the place where the underwear factory used to be..."
Just look at typical business application code no matter whether Cobol, Java, C, or VB.
My point is that you won't have trouble getting "Joe VB" to write in C#, probably just a bit more effort than teching them VB.Net - the problem is somebody who knows VB5/6 really well. Resistance may be futile, but resist they will!