I hear what you are saying and I've seen people who get paralyzed like that, but I'd say that 95% of the time public speaking is not something you must do. So, if it that "painful", I'd say just don't do it. The world won't end.
Build is not a wide public conference, it is intended to be for developers. Ignite conference (which is this week) is the one for decision makers (http://ignite.microsoft.com/#fbid=OzEF049y498).
Samsung is the biggest cellphone maker in the world and they put Bada on a lot of their phones and 95% of the owners of these phones don't know what Bada is. This makes total sense numberwise, but doesn't say anything about Bada's popularity. It's totally like Symbian was the biggest "smartphone" OS just a couple of years ago, just because Nokia was the biggest cellphone maker. Guess how many Nokia owners knew the word Symbian back then?
Yeah, my daughter (13) was explaining something to her friend like:
D: there's this thing on Android too
F: what's Android??
D: your phone!
Still way more of Android users know that they have an Android phone than Symbian/Bada. Actually most likely no less than iPhone users knowing the word iOS (doesn't matter that much in iOS ecosystem though).
The question is: would someone working on 100k salary invest real 50k into a startup? And the answer is 99.9% no. They'll just spend the 50k on fancier food and other crap.
Your problem is exactly what I like about it. I've found much richer discussion than I ever had on Facebook or Twitter precisely because of the fact that it fits the niche of Facebook and personal blogs but doesn't entirely capture the blog area. If it attempted to more completely capture the blogging aspect then I could imagine it getting problematic really quickly, though.