194w ago - Today GeoHot has posted a few pictures (below) with the title "Custom Themes?" on the latest PlayStation 3 blog entry, however, no other useful details are available of the PS3 hack demonstration.
To speculate, it appears to illustrate modifying the PS3 GameOS XMB memory areas, but this was already known over a month ago when word first spread of the PS3 Hypervisor lv2 being dumped and reversed.
It's an RCO file edit, just like RCO edits on the PSP (almost same format too). RCO files are resource files for VSH plugins, live in the dev_flash, and aren't signed. To edit them on your system, patch your hypervisor to allow encrypted access to the partition (flash on old systems, hd on new), and mod ps3pf_storage. dev_flash is just a FAT partition, mount it in Linux and change what you'd like.
Nevertheless, it looks like progress is indeed being made editing and replacing an RCO in /dev_flash/vsh/resource/, although it would be nice if the information was made public so that other PS3 Devs in the scene could join in the fun.
From NDT: Le foto sono vere al 100% Ha modificato gli RCO dal dump della ram ma dato che non sono signed questo significa proprio poco. Si vede che stava cercando anche lui qualcosa da postare.
Rough translation: The photos are real 100% Changed...