Sharepoint - SharePoint 2010 branding - I see it (as site admin) but rest users don't

Did you remember to check in the master page?

Site Actions > Site Settings > Galleries > Master pages and page layouts

Find your master page, select it and select Publish then Approve

don't forget to publish your master/layout and site pages.

A common mistake that I have made a thousand times.

We never did figure out why the items are greyed out or why the check-in box didn't have the option to 'publish', however, we did discover that the CSS we added wasn't published. Once we published it (and corrected the path to the images), it was viewable by all users. Thanks to everyone for your help!