We'll be fine, Harbaugh has prepared for a situation like this. It's almostl ike he knew it was going to happen. Remember when everyone was surprised with us keeping Celek? Now Walker is hurt and he'll contribute.
I think we'll plug in AJ Jenkins to replace Williams and then we'll move form a two headed running attack to a three, using Gore, James and Jacobs with the occasional Dixon sighting. That'll change up the dynamic big time but it should still work out.
Jenkins was looking good near the end of preseason and he'll only get better with time.