1. Cheer up / Act like a start-up again
Nope, there are shareholders to answer to now, so there's no going back. Squeeze the users balls for maximum monies.
2. Turn twitter into the real-world
Nobody has ever achieved this, and it may not be possible. But it's also a myth because people act like total dicks in the real world too.
3. Make the ads more relevant
All ads suck, and all advertisers are creepy as fuck. No exceptions.
4. Re-open the API
You may get some suckers, after all people write Apple apps all the time. But that trust has been violated once. Why will people trust that twitter won't shut the API for a second time. I'm more likely to trust Chairman Mao's "Let a hundred flowers bloom".
5. Purge corporate culture / Be more open.
The trend is always towards less openness. Abandoning the web towards native apps. Google disposing of experimental stuff to focus on corporate cash cows. Micropayment scams. Open-ness and niceness were excess from an investment bubble. Now shareholders wanna get paid.