The official Ubuntu 10.10 Maverick Meerkat countdown banner is not available yet, but a lot of designs have been submitted to the Ubuntu Wiki. All of them look amazing but only a few are already functional. So why not use them on your website or blog already?
Here are the banners which you can already use and their corresponding embedding code:
David Laurell's simple design
<iframe src="http://daverix.net/maverickcountdown/iframe.html" frameborder="0" height="150" width="180" ></iframe>
Cassidy James' 10.10 Calendar Design
This Ubuntu 10.10 countdown banner displays "Coming Soon" until there are only 38 days left.
<iframe src="http://cassidyjames.com/downloads/maverick-iframe.html" frameborder="0" scrolling="no" width="180" height="150"></iframe>
Joern Konopka's Entry
This banner comes with some awasome HTML5 transitions (so make sure you use a HTML5 capable web browser) as well as the new Ubuntu font.
You can find a lot more Ubuntu Countdown banner designs @ the Ubuntu wiki. Hopefully more of these will become functional soon.