Bump and color combiners have been re-done from scratch with full SSE support and have been optimized at processor level to practically have zero impact on rendering times. Very simple and powerfull helping shaders.
Color_Mix2 is a fully color correction node with all Photoshop blending modes and much more included support for alpha channel.
Bump_Mix8 instead can layer up to 8 bump2D/3D (or any shader that outputs perturbed normals) nodes and comes with powerful parameters to let you optimize your bumps under various situations.
Both let your hypershade be very tightly organized for improved productivity.