I generally prefer email to any other form of electronic communication. It's sortable, archivable, easily formed into lists, decentralized, encryptable, supports attaching images, well-known, implemented in a number of protocols... While you could implement a shiny-for-the-laypeople status code parser, email as a system works unbelievably well.
This. I shudder every time someone mentions replacing e-mail attachments with Dropbox/iCloud/etc., which somebody already did in this thread. With e-mail, I am beholden to nobody; and if I pay some company to handle my e-mail, it's only because I voluntarily chose to do so. I could drop that company at any time, fire up my own mail server, and have a 5TB mailbox with 10, 20, 30 years of searchable history if I wanted to. I can also access it with a whole bunch of free and open-source software, from ESR's original fetchmail all the way to the latest alpha of Thunderbird.
Every other messaging system that I've heard about, on the other hand, is either held hostage to one company's proprietary platform or clearly not intended for people who need to look up conversations they had 10 years ago.
So please, folks, by all means fix what's currently wrong with e-mail. But please think twice before suggesting that everyone replace it wholesale with some proprietary cloud-based TODO app.