What Does It Take to be a MS Developer Evangelist?

Just what does it take to be a MS Developer Evangelist? I suppose that there's a lot of travelling, you have to be comfortable meeting a lot of people, you need to know a lot of different MS development technologies, and apparently, you should also feel comfortable doing this type of thing in public:

http://myst-technology.com/mysmartchannels/public/item/104272

(Watch the video on Josh's blog)