This isn't a troll, I promise.  I'm actually going to be doing this tomorrow.

My normal Ruby spiel is geared more toward the differences between
dynamic and static langugages, and the power of blocks. In other
words, "Hey, look at what you can't do in Java."

This is a whole different scenario, because these people are coming on
board to be web application developers, and their previous programming
experience is 100% mainframe-based.  They aren't going to know HTML,
XML, Java, C++, etc.

What are some key points I should make sure to cover for procedural programmers?
Things on my list so far:
1. Variables don't hold values, they are just labels.
2. Objects are nouns, methods are verbs.
3. Structure keeps you sane.
4. Duck typing makes testing easier.
5. Rake as an example of something procedural in an object-oriented language.

That being said, I've been immersed in OOP for so long, I don't
remember what the hurdles are.
Thoughts? This is going to be a three hour session, wherein I need to
cover Ruby and at least the bare beginnings of Rails.  Obviously an
in-depth treatment of either of those things is impossible in that
timeframe, but I do want people to leave feeling like it's not a
magical tongue spoken by elves and wild spirits.

Thanks,
--Wilson.