Yeah it's not a rebrand, but it's not a new chip either. In previous years nVidia would release a new architecture eg GF100, then respin a new chip with some improvements eg GF110. This year they 'dropped' the top chip (GK100) and only released the respin (GK110 - aka titan), whilst not respining the lower chips at all (hence still GK104 rather than GK114). They've created new products with binning and fusing of cores, as they do for different market differentiations as normal, but they're not new chips, let alone new architectures.