First of all, thanks, F#-team is making a great job. And these kind of videos are good to get a great language some attention.
But I have some small critics to these samples... Samples teach programmers so they shouldn't teach bad things. They should teach best practices, not tricks or hacks.
Tricks are good to know also... But maybe these samples could be divided to two sections: 1. howto, 2. tricks.
1. Why to teach programmers to use mutable state so much? There is a very good reason why mutable state is not default in F#.
2. Why using inline keyword in samples? Inline is usually just for interactive. Msdn says this: "you should avoid using inline functions for optimization unless you have tried all other optimization techniques". So why do we need this in basic samples? http://msdn.microsoft.com/en-us/library/dd548047.aspx
I'm F#-programmer, and one of those who thinks that Design Patterns are common "best practice" ways to manage object-oriented problems that doesn't exist in functional language.