I do like the fact that Buzzword seems pretty quick. On initial look I am surprised the only share feature is via sending an e-mail. I would think that it would have the option to simply share publicly like many others (which it may somewhere, I need to look around a bit more before saying that it can't for sure).
I probably need to share to one of my other e-mail addresses to see what that looks like. I must say the other thing one finds amiss is the fact that under "Save As" the formats listed are Buzzword Document, which saves within the Buzzword web environmet, or File, which gives the options of Microsoft Word (.doc), Microsoft Word 2003 XML (.xml), and Rich Text Format (.rtf). The one missing from the list; Adobe's own .PDF. I know Adobe use to allow individuals the ability to create PDFs online via subscriptions, if they still do, they might be taking a revenue stream away from themselves if they add the PDF option, but as many others offer that capability, what will draw one to Buzzword and set it apart from the others.
From the site:
Buzzword, the first real word processor for the web, is a breakthrough in collaborative authoring for documents that matter. Many online pundits agree with us. Check out The Buzz page.
You can also check out the Buzzword Blog.