Jon Mitchell, writing for ReadWriteWeb, captures what’s unique about Drafts well:

Drafts is a new starting point for typing anything on an iPhone. Every time you launch the app, there’s a blank note ready. You can jot down a tweet, an email or a note immediately, and then send it to the right place. There’s no need to worry about file names or folders. It’s just the fastest way to capture text. It might solve problems you don’t even know you have.

I even get quoted in this review, so you should definitely go read it.