Basically, if we want all OE packages in there so that the user can install non-included things as well, we'd need to setup the server so that it bakes all other packages from our OE Clone (http://git.openpandora.org/cgi-bin/gitweb.cgi?p=openembedded.git;a=summary) as well, but doesn't include them in the image, but only in the feeds.
Once that has happened, we can easily switch the Pandora to use our feeds.
No need to include all OE packages. The opkg config files (in /etc/opkg/) let you specify multiple feeds at different priorities. The arch.conf file lists feed names and relative priorities, while *-feed.conf gives the corresponding URL for each feed. Simply set the Pandora feed as the highest priority and the Angstrom feeds lower; that way, all Angstrom packages are accessible unless there's a Pandora-specific version that supersedes it. Of course, not all Angstrom packages will necessarily work next to Pandora packages. But if a package is found to need Pandora-specific fixes, the fixed version can be added to the Pandora feed.
I hope that helps.
Randy Heydon