Complaining that email is disappearing ignores the fact the business letter has pretty much disappeared. Heck, it's kind of like complaining that we just don't send as many telegrams as we used to.
Suggesting we're going to lose some kind of texture or depth to our communication because we're shooting 160 character txt messages at each other ignores the fact that we have more ways to communicate than ever before, and the bulk of these ways to communicate are still using the written word, Skype and "forward facing cams" on cell phones aside
It is true that the medium changes the way we organize and manage those thoughts, but the way we communicate changes more with your culture (family, friends, business, etc.) While I despise smileys and LOLs, it's no different than despising street slang or corporate acronyms. I don't see many emoticons in emails with attorneys, although I admit I've seen them from contacts in the Federal government...
I guess what I'm saying is that when people bemoan the death of email, they're bemoaning the death of a format, of conventions for how to express yourself. The long, in-depth letter died a long time ago, although one may consider that it was replaced by the blog -- long in-depth writing still exists, even if there is a flood of BRBs and CUs in Facebook.
When we have a story about the death of communication, then I'll pay attention, provided there's still a medium to deliver the message (clay tablets work, but you probably want to keep your message short...)