I was noticing a few little tweaks in the Google Reader interface tonight (unread counts now go up to 1000+ instead of 100+, there’s a “Loading” spinner animation, etc.), and then I saw this post on the Official Google Reader Blog with the big news – they’ve (finally) added search to Google Reader:
You can search all of your feeds, search only within a certain folder, or only within a certain feed (by picking in the drop down). Very nice.
I’ve wished for this feature several times in the past week, to try to find something I vaguely remembered reading in a feed. I can’t wait to try it out. Thanks, Google Reader Team! 
A couple other tweaks I noticed: you are automatically moved to the next folder with unread items when reading with the spacebar or “J” key. And the “Subscribe” interface has changed a bit:
