evolving instant-voice-messaging and instant-video-messaging apps that will make today's e-mail and IM seem crude.
I doubt it, many people love the annomytity that text communication allows, it also is usually much more to the point. I for one am not in a huge hurry to have video conversations with people on the web, at least 99% of them. And voice, well I already have a phone.
Remember when video phones were supposed to be the next big thing - we all have one of those now right?