I think the App.net guys made an astute observation that the biggest hurdle to attracting developers was doing away with the perception as the platform as a gamble for developers.
It doesn't hurt that the Tapbots guys used the Tweetbot apps to piggyback on, of course.
Unlikely (read: impossible). Even if they could have ported it in the 6 days since that announcement, there's no way they rammed a new app through App Store approval that fast. They'd probably already have had to have submitted it before the announcement given current wait times.
The reward program was announced a week before Netbot was released (that is, today). Doesn't seem like the reward program was around when they decided to port over Tweetbot.
I think the App.net guys made an astute observation that the biggest hurdle to attracting developers was doing away with the perception as the platform as a gamble for developers.
It doesn't hurt that the Tapbots guys used the Tweetbot apps to piggyback on, of course.