I wonder if Twitter will become like MySpace -- a mass market/middle school/music/urban ghetto, with everyone smart enough to move to another service doing so (which was Facebook at the time).
If the tech/vc/science community moved to app.net, the only thing left for me on twitter would be businesses abusing it as a form of RSS, which is by far the easiest content for them to publish to both Twitter and App.net in parallel. So really there are about 5k and maybe up to 50k people who need to move to app.net for me to no longer care about Twitter, and presumably at least 2500 of them have already signed up.
If the tech/vc/science community moved to app.net, the only thing left for me on twitter would be businesses abusing it as a form of RSS, which is by far the easiest content for them to publish to both Twitter and App.net in parallel. So really there are about 5k and maybe up to 50k people who need to move to app.net for me to no longer care about Twitter, and presumably at least 2500 of them have already signed up.