Looks like we've (almost) solved the mystery of PlayStation 3's FCC-bound CECH-2501 models. Sony just announced a "classic white" PS3 Slim (as opposed to the "ceramic white" original) for Japan, model CECH-2500, coming July 29th with 160GB HDD. For 34,980 yen (about $400 translated to US currency) you can now start off with 320GB of storage in your "charcoal black" model -- not to worry, the aforementioned 160GB still retails for 29,980 yen ($342). So, when are we gonna see this elsewhere in the world, hm?
Update: Post edited to make clear that the new "classic white" model is only available with a 160GB HDD.