Features List b2 or Cafelog WordPress 0.72 WordPress 1.0
Trackback Support
Pingback Support
Template Tags
Right click bookmarklet
RSS 1.0 and 2.0 Feeds
User level control
Time Zone Control
Online Template Editing
BBCode, GMCode, smilies supported
Calendar Support
Archives
Teams
Blogging via email
Spell Check
Preview post
Edit Timestamp of post
Search for posts
Comment notify via email
Text blog from cell phone functionality
Weblogs.com and blo.gs auto-pingers
Password protected posts  
Cursor-aware quicktags (like using a fancy text-editor)  
Improved API support: full or near full support for the Blogger, MetaWeblog, and MT APIs  
New template design from Dave Shea  
New configuration method, no more editing files!  
New Blogger import  
Improved upgrade and install scripts.  
Improved post and edit interface  
RSS feeds for comments  
RSS feeds support Conditional GET  
Improved XHTML auto-formatting  
Improved Link Manager with recently updated functionality  
Geographical data support  
Improved image upload features  
Improved calendar  
Improved smilies function  
No more invalid characters  
Increased customizability  
Comment RSS Feed  
Private posts functionality  
Safe as Draft Functionality  
Meaningful URLs with mod_rewrite    
Edit This links next to every post/comment if you are looking at your own blog.    
multiple categories for a single post    
Comment moderation    
Atom feed    
Trackbacks from posts that are saved as drafts    
Consistent naming scheme with WordPress    
Basic and Advanced editing screens    
Better link management with XFN and RSS built in    
Built in hack management, so easier upgrades    
Safer comments (not as easy to hack or break) using KSES filters    
More template tags    
Smoother admin interface    
And a bunch of other stuff I am not thinking of