Firstly, this new architecture (GK104) has a great number of cores (192 versus 32 of the Fermi architecture) sharing a single control logic within a stream multiprocessor (SM). Internally, each SM is SIMD, so this move is bad for divergent kernels, i.e., algorithms containing if-then-else constructs.
Actually this is not true. The SIMD width (warp size) is still 32. Divergent kernels won't suffer more with kepler. Maybe you got the wrong impression because nvidia's diagram with its architecture might be oversimplified.