I think the demand on talent for marketing in a startup is almost the same as it is for every other role: Generalists with a very clear bias toward action that they can do themselves.
I emphasized, in my mind, the more important part. It's one thing to have brilliant strategic thoughts, but let's be honest -- if you can't actually execute on anything, then you're going to have a hard time working in a startup. You have to be able to get your hands dirty, and for marketing this might be organizing events, hitting the streets, setting up email templates for consumer engagement, etc.
Hire from a Big Co? Sure, but just make sure you know what you're getting.