Think about it. Telegrams were cutting-edge for almost 100 years. Fax machines were just as cool for a couple of decades and are not quite dead just yet. Email has only been with the worldwide masses for a little over a decade and now seems less than efficient and pretty spam-heavy.
Unless you are sending documents, images, etc. that are too timely and expensive to print and send or even fax, the volume of email for a typical decision-maker demands filter after filter (real people) to get to worthwhile communications. One friend of mine receives 200-300 emails a day and must wait for his Sherpa to deliver the ones that are worth his consideration. Quick replies just aren't an option and are pretty annoying for all involved.
Adobe has certainly made email more efficient for large documents, images, and projects, but that's about the only bright spot.
Next Gen handheld options (quick texts, social network tools, just plain old phone calls) may just offer us the further obsolescence of routine email, much like DVD's to VHS tapes, CD's to cassettes/albums, and old Ma Bell to Western Union herself. The more things change....
