If you haven't checked them out already, go to Symfony's "Talks" section.
Now, this is great for all of us Symfony developers, but it's also a good thing for php developers in general.
If you're a Symfony developer already, you know what you're interested in there, so I'm going to focus on what non-symfony developers can get out of this treasure trove. Also, these videos are also available in French through the talks section.
Talks that apply to everyone
Designing HTTP Interfaces and RESTful Web Services -- David Zuelke gives an excellent presentation on what restful web interfaces mean, and was actually the driving inspiration behind my dedicating my Symfony Live hack day project to the Accept Header Service Provider for Silex, as well as this pull request for the Symfony core.
Talks for programmers
Symfony2 components to the rescue of your PHP projects -- Xavier Lacot goes over how you can use symfony components in your every-day php projects to make your life easier.
ORMs don't kill your database, developers do! -- Guilherme Blanco shows you some ways to optimize your setup when dealing with an ORM. I've heard there is some controversy on some suggestions within, but I think that just makes it juicer.
Dependency Management with Composer -- If this is anything like his talk in San Francisco (and I'll just go ahead and blindly assume so!), Jordi Boggiano gives an excellent overview of what you can do with Composer and how to take advantage of it right away.
Talks for frontend developers
How we built the new responsive BBC News site -- Really. Need I say more?
Still need more?
Richard Miller gave a talk on what you get from a full stack framework. I haven't watch this, as I have already drank that particular kool-aid, but if you haven't made the leap yet, I'm sure he presents some compelling arguments. If, after it, you're still not sold on full stack frameworks, just wait until Dustin Whittle's Silex talk from San Francisco is up. It will blow. Your. Mind.