I just created a new blank site installation using v2.2.1, build 20110705.
On some of my other EE2 sites, I haven’t had a problem creating a new template group in my file directory (along with an index.html) file and having it automatically recognized as a template.
Unfortunately with this new installation, unless I log into the Control Panel and access the Template Manager first, I get a 404 error.
I am using the MediaTemple (gs) hosting package.