Let's get this out of the way first: if you're looking for updates to Photoshop, move along, there's nothing to see here. Ditto for Illustrator and Fireworks. While there's a lot going on in Adobe's bump to Creative Suite 5.5, those products will retain the CS5 moniker. As for the rest of the crew, the updates to the applications fall into four categories: single source, multiple target workflow enhancements; improved interapplication integration; performance boosts and interface tweaks; and broader support for a variety of formats. I'm not going to list all the various new features and tools--that's a great way to lose the forest for the trees--and instead hit some of the highlights. If you're looking for detailed information on any particular product, you can find it on Adobe's site.
So what's new? InDesign makes the EPUB format contort in ways it was never intended to; that is, rather than output basic text documents, you can now do fancy-schmancy multimedia stuff like embed video and audio, determine article flow, and dynamically resize images. If you're a big publisher and use the Digital Publishing Suite, you can create .folio files with interactive image overlays that support audio, video, slideshows, and hyperlinks. To me, though, the most noteworthy addition is mapping styles to HTML, EPUB, and PDF tags, as well as the ability to add CSS class names and custom tags.
Flash Pro and Catalyst have improved roundtripping with each other. Catalyst has some interface tweaks, including a new common Library panel. (I'm not a Flash user, but I have to say: Adobe's just adding an Align panel now?) You can also define projects as resizable with parametric scaling. Flash Pro has been updated to support the latest versions of the Player and AIR, with source-level debugging on AIR devices. There's enhanced layer handling (including copy/paste and duplicate), parametric object scaling relative to stage size, and symbol rasterizing to improve playback performance.
On the video side, Premiere Pro, After Effects, and Audition all seem to play better with each other, and incorporate interface tweaks and performance boosts. Adobe boosted the selection of GPUs supported by Premiere Pro's Mercury Playback Engine, as well as upped the variety of operations that take advantage of it. There seem to be improvements in handling RED workflows and Canon XF video, as well as a new Merge Clips feature for syncing that pesky timecode-free audio that comes from dSLR shooting. Media Encoder has new presets for rendering to a variety of screen sizes. After Effects incorporates the Warp Stabilizer image-stabilization feature about which Adobe released video previews recently. There's also a set of depth-of-field tools to make your video look like it was shot with a dSLR, along with its artistic antiparticle, 3D stereoscopic editing. Audition now runs natively on the Mac OS, and supports native 5.1 surround editing.
Finally, as you'd expect, Dreamweaver beefs up its HTML5 and CSS3 implementations with an enhanced CSS panel and CSS3 code hinting, and updated Live View to support CSS3 attributes. For multiplatform coders, Adobe improved the Multiscreen Preview panel. Now you can see how your beautiful designs will render on all sorts of tiny device screens simultaneously!