In a “Gmail already had it for awhile” update, Google Apps appears to be adding Themes support (screenshot above). I only noticed this on one of four Google Apps accoutns I have, although this particular account had a glitch which held back Gmail Labs for months after other Apps users saw it.
Maybe a olive branch?
Either way, now I’ll spend a little while finding my favorite theme. Thanks Google for an early April Fools’ Day gift.