WordPress 2.5, the culmination of six months of work by the WordPress community, people just like you. The improvements in 2.5 are numerous, and almost entirely a result of your feedback: multi-file uploading, one-click plugin upgrades, built-in galleries, customizable dashboard, salted passwords and cookie encryption, media library, a WYSIWYG that doesn’t mess with your code, concurrent post editing protection, full-screen writing, and search that covers posts and pages

User Features
Cleaner, faster, less cluttered dashboard
Dashboard Widgets
Multi-file upload with progress bar
Bonus: EXIF extraction
Search posts and pages
Tag management
Password strength meter
Concurrent editing protection
Few-click plugin upgrades
Friendlier visual post editor
Friendlier visual post editor

To know more about this and other Important Features Rad Here