[eschwartz]

No it won't, but it will nuke the MKK (which KUAL relies on) as well as the "bridge" which restores the jailbreak after a firmware update. (Firmware updates do remove the jailbreak.)

Basically, if you do reset to factory defaults, reinstall the jailbreak immediately. But it is a much better idea to not do a reset to factory defaults, since you can just delete the contents of the "documents" and "system" folders instead, which leaves the jailbreak/hacks as well as your registration info alone.

EDIT: And as you mentioned collections below, it also leaves your collections database alone. Specifically, the non-synced sideloaded collections groupings.