2 and 2.2 are different almost completely so in order to upgrade, you have to uninstall 2 so make sure to backup your web data and databases before uninstalling
If I upgrade to 2.2 - will that change my versions of Apache, PHP, etc??? More importantly, I'm assuming it will not remember the PHP options selected, like CURL, etc....?
This would be pretty dangerous I think - once I uninstall, and install 2.2, we would have to test all the applications to make sure everything works....