I recently completed a fresh install of Exchange 2010 for a client. After moving a few mailboxes to the new server I wanted to test the OWA. When I browsed to https://(server)/owa it threw the normal SSL cert error but after I accepted the certificate the site would not display the normal OWA logon page.
The solution is to install the IIS role service of Static Content.
After I installed the role service and restarted the site in IIS the OWA logon page displayed correctly.