From the Q&A [of] Anthropologist Mizuko Ito

Q: What are some of the factors that determine how much impact a technology is likely to have?

A: I think the main factor is the degree to which it builds on people’s existing practices, lifestyles, and social lives. That’s how you get these breakthrough technologies, like text messaging.

That's one reason the Blackberry works so well. It (just) takes email and adopts it for the mobile phone. Now with disruptive technologies this takes a bit longer, but then...;)

See also:
What is the ultimate mobile device for now?