Details are coming out today about the new CS5.5 update. Adobe's site is loaded up with info which I've aggregated below. They are saying we'll see a release of this update in early May and you can pre-order your upgrade right now.
One of the most interesting new details about this release is that Adobe is going to start offering a subscription service that allows you a number of options to pay an affordable monthly price for use of either individual applications or a whole suite. See this video for details: http://tv.adobe.com/watch/cs-55-design-premium-feature-tour-/cs-subscription-overview/
List of CS5.5 related videos and articles on adobe.com:
Introducing Adobe Flex 4.5 SDK
What's New In Flash Builder 4.5
What's New in Dreamweaver CS5.5
Introduction to Flash Catalyst CS5.5
Understanding new Flash Catalyst CS5.5 and Flash Builder 4.5 Workflows
Introduction to Flash Catalyst CS5.5 (video)
Wireframing and Prototyping in Flash Catalyst CS5.5 (video)
Importing Artwork in Flash Catalyst CS5.5 (video)
Flash Professional CS5.5 Features
Stabilize Shaky Footage with the Warp Stabilizer in After Effects CS5.5
