Looks like Guy Kawaaki was in fact hinting about the Motorola 'Moto X' phone back in March. He linked to a video about Porsche customization and asked, "Wouldn't if be cool if you could personalize your phone like this?"
Motorola will be releasing this ad in newspapers around the country tomorrow before the 4th of July holiday. The most interesting portion is about the design:
"The first smartphone that you can design yourself. Because today you should have the freedom to design the things in your life to be as unique as you are."
Not much details are available, and it's unclear whether or not the customization will be more than color choice and extend to screen size or something else.