Like many people, my preference is Linux/Unix for hosting/servers but I'm trapped working in a Windows Server environment. There are also a lot of IIS 5 and IIS 6 servers still out there. I'd like to see more instructions for installation that are IIS-specific (that included recommendations for the best way to install PHP and run SilverStripe on it. (for example, changes to the php.ini file like whether one should, or should not, turn on auto_detect_line_endings).
In particular, we need a good (free) way to handle the rewrite stuff. I think that the IIRF looks like it should work, but since it uses its own .ini file instead of reading the .htaccess files, we need some regex guru to translate the rules that SilverStripe needs (writes in the .htaccess file) and translate it into the IIRF instructions in the .ini files. (Example .ini files are here, including one for Joomla). If someone can provide one for SilverStripe, I'll bet they will include a link on their site to it also.
This would open up SilverStripe to all sorts of additional potential users.