I have just returned from Stallman's lecture. It was a very nice talk but I must admit that I haven't learned much that I didn't already know.
He talked about the definition of freedom and discussed various threats coming from not having those freedoms. Obviously, he did not omit to send a few harsh words in the direction of MS, Sony, Apple, Amazon's Kindle (or as he'd call it 'Swindle'), to correct a few audience speakers for using the term 'open source', and to criticise governments' actions to invade our privacy.

Part of the reply to many questions from the audience was: Don't be so defeatist!
This I think is a good message to pass on.

It'd be nice to have more such events/lectures in London.

Are videos of the lecture available?

There was a guy recording it using some professional equipment but I don't know where it's going to be released.