If you look under Quick Links in the text navigation menu (or in your USER CP) you will now see a section called "My Smilies". This change allows you to upload and use a personal set of smilies just for your account.
The explanation on how to use the feature is inside of the My Smilies Control Panel.
Here are a couple smilies resources to get you started.
Or just search good for cool smilies, funny smilies, etc
Like just about everything that gets changed, I'm sure someone (probably using IE.. lol) will have an issue with it.. just let me know and Ill add it to the rolling list of things I break and need to fix...