Nice landing page. I did have one question under the first paragraph it says: "...the to field will be pre-selected so all you have to do is start typing." How would it know which contact to fill the "to:" field with?
Also, please realize this is just a concept and further research will be put into the it if it goes into development. A swift workflow is the biggest goal.
I think using email to shoot off "quick questions" (such as the message depicted on the page) to people is an abuse of the medium - that's what Twitter and iChat are for.
Often it's a sentence fragment, such as "Can you," followed by a continuation of the sentence in the body.