Neocrisis have loads of high res pics so check 'em all out. Some are Japan specific like the protective cases, D-Terminal AV cable and AC adapter I guess.
These are probably the most interesting:
Bluetooth Stereo Head-set/phones Receiver (due January 2010 in NA/PAL regions)
PSPgo Dock Revealing angles at last
Stiff Leather Case with Strap (Japan Only)
Soft Zip Case with Extra Storage Pocket (Japanese Design) I prefer the American version
Soft Pouch with Strap (Japan Only)
I posted the
North American lineup here.