Nikon & or Canon I have both but,,,,

I looking in dumping one system out intirely the reason is it makes no sence in owning both financially. so i am going to post this in both canon and nikon forum so i can get opinions from both sides

im torn between the two brands, nikon side i own the d3 - d300 and almost every lens out there, new generation, beside the 400mm + telephotos, same thing on canons side, own the 1ds mk3 and canon 5d mk2,.. and all lenses, im thionking about the 21 mpixel verses the 12 on the nikon side and that is making me lean towards keeping canon, but i love the lenses on nikon side and the easy to use features of nikon and speed and the speedlight system of nikon. so u guys tell me, what would u do if u had to keep one system and sell off the other?