From the Twitter blog:
Rather than continue to make changes to the QuickBar as it exists, we removed the bar from the update appearing in the App Store today. We believe there are still significant benefits to increasing awareness of what’s happening outside the home timeline. Evidence of the incredibly high usage metrics for the QuickBar support this. For now, we’re going back to the drawing board to explore the best possible experience for in-app notification and discovery.
Half of the above I believe to be a lie, specifically: “Evidence of the incredibly high usage metrics for the QuickBar support this.”
Why remove a feature if it is truly that popular? You don’t.