Google Reader shows more contextual actions for each feed. Now you can rename the feed's title and change the tags without going to the settings. And if you do go to the settings, Google Reader Team says everything will load faster.
If you subscribe to a feed, you'll see a text that says: "You have subscribed to [this feed]. Add to a folder." Hopefully, all your feeds will be categorized. (And hopefully, someone will decide between tags, folders and labels.)
The new features were available last week for a while, but some problems with Internet Explorer 6 caused a roll back until they were fixed.
If you have suggestions for Google Reader, check this wiki at Google Groups.