Scott Smith from Screenwriting from Iowa has a post about companies creating content as advertising. I think it's another interesting branch of (mostly) web entertainment and more opportunities for writers.

http://screenwritingfromiowa.wordpress.com/2010/09/30/branding-entertainment/

I wonder, though, how much of the content is comedic v. dramatic. I think advertisers are going to gear towards comedy. Comedy also seems more viral. I'm much more like to share a funny 5 minute clip with friends than a dramatic one.