Nothing wrong with choice having multiple options for XBMC but there is also reinventing the wheel and wasting resources.
It strikes me that GeeXbox and LinXBMC (by Sam Nazarko) both have the same goals, Sam did by far the best distro for the Raspberry Pi and he is looking to extend that further to many of the same platforms GeeXbox runs on.
Maybe all the parties involved treat this as a passion project and have no interest in teaming up but it wouldn’t hurt to reach out and see if mister Nazarko would be interested.
P.S. Even if you dont team up for LinXBMC consider changing the name of GeeXbox. To be blunt it sounds odd and Xbox has nothing to do with XBMC these days. Sadly GeeXbox still has an extremely low profile but it also means it’s not like your losing much changing the name.