For some neat Blitzkrieg campaigns and fixes, be sure to check out GordonCZ Works!
http://www.gordoncz.com/blitzkrieg/index.html

It covers some of the best collaboration made campaigns packs and fixes form Blitzkrieg-Portal (before it died...) and are available there for ease of download.

The site explains and covers what each pack contains and how to install It, so I'm sure I don't have to link or explain them here.

Just be sure to check out the 'Utilities' tab and download the ailogic and winter building fix, as it will make any vanilla experience even better!