Holiday and a lot of catch-up work interfered, so I am a bit late with the news: Six Apart launched a beta version of the new Movable Type Theme & Plugin directory and a thoroughly renovated www.movabletype.com. It looks gorgeous.
Recently in Plugins Category
I just released a little plugin I needed for another project. It adds a 'bitlyfy' template tag modifier to Movable Type that lets you turn any URL into a bit.ly shortened URL directly in your Movable Type template code. Simply add bitlyfy="1" to any template tag that outputs a URL, and it will output a bit.ly link instead. Download the Bitlyfy Plugin here, docs and source are here.
I recently needed a quick way to use the values of a number of configuration directives in my mt-config.cgi file directly in a template. So I created a little plugin that adds an <mt:configdirective> tag to Movable Type. You can use it to do things like <mt:configdirective name="SearchThrottleSeconds"> for example. Warning: it can also be used to expose your database password etc., so don't install this plugin on a system where anybody can edit the templates. The plugin can be downloaded here: https://github.com/mschenk/mt-plugin-configdirective