What worries me most though, is that some businesses and governments no longer appear willing to use e-mail for external formal communication at all. When I asked my bank (ING in the Netherlands) how I could e-mail them with a question, they stated that e-mail is no longer an option (not even via a web-form), and that I would have to use Twitter direct messages, Facebook, or a web-based chat-page for any digital communication with them.

E-mail may not be hip, but I do get to keep an archive with sent and received communications that I can easily backup and keep for future reference, just like I do with paper mail (at least the important stuff).