Share 'is it worth upgrading to an FX format camera?'

hello all.. i currently shoot with a nikon d90 and have been blown away by the image quality and the awesome features of the camera.. i'm thinking of getting a second camera for doing a little bit of videoography as well (the nikon d7000 when it comes out)..now here's my dilemma.. i'm not sure whether i should stay in the DX realm for photos and film, or get a full frame FX camera for the photos…