Pros: Span- and split-column paragraphs, multiple page sizes, Illustrator-style Layers panel, numerous simplified transformation options, dynamic metadata captions, text track changes, and an expansive new set of animation and interactivity features.

Cons: SWF export doesn’t include scalable animations, no split columns in table cells, longstanding rotation behavior removed, Document-installed Fonts feature on Mac platform supports OpenType and TrueType only.

InDesign CS5 delivers some long-requested features and many little things that add up to a lot. The new version also introduces impressive new features that let print designers stretch themselves into the new paradigm of document creation, which now includes interactivity, animation, and video.
Some of this new features are:

1. Multiple Page Sizes; Span, Split, and Balance Columns
2. Simplified Transformations and Selections
3. The Gap Tool; Gridified Frames and Super Step-and-Repeat; Layers Rebuilt
4. Metadata Captions; Mini Bridge
5. Interactive Documents
6. Workflow and Collaboration; (Not Quite) All The Little Things
7. Buying Advice

To read more: http://www.creativepro.com/article/review-adobe-indesign-cs5