New Features in Flash CS5
This is a part of a post published in http://askmeflash.com/article/18/flash-cs5-new-features-and-a-comprehensive-overview
"New Text Engine: Text can now be handled in a more improved and better way with the introduction of more control features. To mention a few important, advanced styling and layout options, right to left text option, columns, threaded text blocks have been introduced.

Embedding Fonts: Embedding fonts is now quick and easy. Fonts embedded can be FLA based instead of Text based. A user friendly window provides all the functions associated with the embedding fonts.

Panel for Code Snippets: A quick access to common ActionScript 3.0 code snippets is possible so it can injected in the code easily and fast.

iPhone Capabilities: Flash Pro CS5 introduces an application packager that can be used to deploy flash applications on iPhone.

Cue Points in Video are now easy to add.

Improved FLVPlayback component equipped with new skins and an option for its live preview on Stage
XFL file format Flash: By default now flash files will be saved in XFL format internally. As the format name denotes, its an XML format which will result in an improved exchange of data with the other Adobe applications.

Uncompressed XFL file format: Uncompressed XFL structure will now make it possible to analyze the parts of the flash file and thus working with the source control systems like Visual source safe.

FXG file format support: It allows CS5 to export and exchange graphics with the other Adobe applications with a complete compatibility.

New Decorative Drawing tool: CS5 provides several new effects with the newly added Decorative Drawing tool.

New Properties for IK bones: New properties like Spring properties have been added to IK bones to create realistic physics effects for bone animation.

Integration with Photoshop CS5: Graphics of Flash CS5 can be edited in Photoshop CS5 and so they can be exchanged between the both directly.

Coding and Formatting Improvements:
Code completion for custom and build-in Classes has been added for ActionScript 3.0.
Custom classes are automatically added to the application using import tag.
While you script, closing brackets { } are automatically added.

Better integration with Flash Builder: Improved workflow between flash CS5 and Flash Builder makes it easy for developers and designers to use both the products together.

Updated AIR Publish Settings: The user interface and Installer Settings Window for AIR Application have been changed to make it more user friendly.

Update in Document Property Inspector: Now it also displays the size of all SWF files generated during movie operations like Test Movie, Publish or Debug Movie.
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New templates added for common type of project templates.

New JavaScript API's are added for motion tweens.

Access to Adobe Community Help..

Live Services are accessible from within the Flash authoring environment."