The title could really be better -- the article isn't about Dropbox users, it's about your feature. Calling for attention in a title rubs me the wrong way.
Let us know too if there are some other apps out there you want to email. sifter seems like one people want real bad thats been taking awhile. My personal fave would be to allow 37s writeboards to be edited right from inline replying to an email.
you can natively email your files to dropbox, along with other input methods like via fax/phone/file upload, etc