Switching to WordPress
I have to laugh at the work-around I was using to have a categories in Blogger versus the simplicity of WordPress. So far I am really enjoying it. It was very easy to import the existing posts from Blogger. I seems very well organized as far as maintaining categories, posts, links (blogrolls). I also like how there are options for creating static pages (like an About page), and then automatically generating a site map off of those.
One really great feature is that you don't have to modify templates at all, which makes switching between templates very easy (unlike Blogger where you would have to merge over your links, etc). WordPress seems to be designed so that all the blog specific information is stored as part of the blog, not as part of the template.
Update: The category hierarchy is interesting. When viewing posts in a parent category, it will automatically go through all of the child categories as well. If a post belongs to multiple child categories in that tree, then it will repeat.
Update2: Just tried out Sidebar widgets for the first time. This is a very good idea. It lets you change the look of your sidebars without affecting your themes at all. There are several interesting default choices (including Flickr photostream). They don't seem to have all of those "Add to Digg" etc badges, but I'm sure I'll find them somewhere.
Update3: I'm really impressed with the HTML Post editor for WordPress. It has just the right amount of features to be very useful (bold, italic, strike-through, lists, block-quotes, alignment, links/images/line-breaks, spellchecker and the ability to look at the raw HTML to fix something to look very specific). I especially like the status bar that shows you which element you are on, so if you want to grab an entire table or a specific row of a table you can.
Update4: The Post editor for WP has a re-sized bar for text entry. That's so cool. The spell-check feature is rather versatile as well, as it will underline in red all of the misspelled words, and then you can right click to get a list of suggested correct spellings. I'm a bit surprised that it doesn't recognize "blog" or "WordPress".