The official check list can be found here.

1. Copyright notices
   • All source files must have appropriate EPL v1.0 copyright notice
   • Source files whose content was created for 3.5 should read "Copyright (c)  2007 ..."
   • Source files whose content was modified during 3.5 cycle should read "Copyright (c)  200x, 2007 ..."
   • All features should have "(c) Copyright Eclipse contributors and others 2000, 2007." in Help > About Eclipse Platform
2. Plug-in and feature identification
   • Check this info from Help > About Eclipse SDK
   • All features should have provider "Eclipse.org" and version "3.5.0.qualifier"
   • All plug-ins should have provider "Eclipse.org" and version "3.5.0.qualifier" except for known special cases (org.apache.*, org.junit, org.eclipse.tomcat and bundles from Orbit)
3. License agreements for features and plug-ins
   • Help > About Eclipse SDK > {Feature | Plug-in} Details > More Info
   • All features should link to the Eclipse Foundation Software User Agreement dated March 17, 2005
   • All plug-ins should link to the plug-in's about.html file containing its plug-in-specific license
4. Extension point documentation
   • Extension points must be documented in the appropriate help book
     • Platform Plug-in Developer Guide; section Reference / Extension Points Reference
     • JDT Plug-in Developer Guide; section Reference / Extension Points Reference
     • PDE Guide; section Reference / Extension Points Reference
   • Must be a link to each extension point that a component has
   • Extension points added in 3.5 must be clearly marked "Since 3.5"
5. API documentation
   • Java API must be documented in the appropriate help book
     • Platform Plug-in Developer Guide; section Reference / API Reference
     • JDT Plug-in Developer Guide; section Reference / API Reference
     • PDE Guide; section Reference / API Reference
   • Must be a link to each API package that a component has
   • API package must have package overview (package.html)
   • All API elements must be documented
   • API elements added in 3.5 must be tagged "@since 3.5" (see bug 190060 for tooling support)
6. API Compatibility
   • compare all APIs with the previous release.
     This can be done manually through CVS or with a tool like PDE UI Incubator ApiTools Compare
7. 3.5 Plug-in Migration Guide
   • Instructions for migrating older plug-ins to 3.5
   • Must describe incompatibilities and breaking API changes
   • Should describe deprecations and places where 3.5 has a better story that plug-ins should more to
   • Located in Platform Plug-in Developer Guide / Porting Guide
8. Documentation
   • Add and update documentation according to the doc check list.
9. What's New in 3.5 Need to review the JDT what's new for RC4
   • Describes the more interesting differences that 3.3 users will see when they upgrade to 3.5
   • Located in {Workbench | Java Development | PDE} User Guide / What's new
10. Release notes
    • Add known problems for each component and other late-breaking news for customers of 3.5
    • Located in eclipse/readme/readme_eclipse.html