Can you add new menu items to the XMB? For example, have the locationfree player and an FTP server under network, and have network update (not really needed), and reboot PSP under settings. Also, maybe have PRX's set up to launch homebrew outside of the game menu. For example, have a PSPRadio icon under the music section, and a PSPPlayerMT icon under the video section.
Also, how possible is it to have PRX's that could run like official PSP PRX's. To have, for example, an IM client under network that would launch over the XMB and behave like the rest of the PRX's (fading when the home button is pushed, and have a standard PSP layout)?