Canon DPP vs Photoshop CS

How does DPP post processing compare to Photoshop CS for editing wedding pictures? Can someone provide details on what editing software works best for editing digital images specifically for weddings?

DPP and PS don't compare.
DPP is a raw converter, PS is a pixel editor.
If you want to compare DPP to an Adobe product, that should be Adobe Camera Raw (ACR).

Any ACR before the latest (4.5, with the new beta profiles) is so far off color wise that it isn't funny anymore. (At least in my case, YMMV).

DPP + PS (whatever version from PS6 on) is a very nice combo. IMO neither can do without the other. (PSCS3 being the exception, since that's the only one to run ACR 4.5).

If you want one application to "do it all", LR2 might be worth looking into.

Then again, also with LR2 you might be needing PS now and again (no biggie if you own CS)

Used to be, choose DPP for colors and ACR (LR is based on ACR) for convenience/workflow. With the advent of ACR4.5, colors are a lot closer to DPP than they were. To a certain extent, it's a wash...especially regarding wedding photos. I liked LR 1.x despite the colors (I had profiles that got me close) but LR 2.0 I really like...aside from some lag issues. No real need for DPP anymore, in my opinion.