In some cities are niche companies starting just for you Jeff. One example of the largest and fastest growing is 1-800-Got-Junk.
You should just call them and talk. The first step is admitting you have a disease. They may have meetings for ClutterAddictsAnonymous or something. At the very least, they will come haul off whatever you pile up, if not help you sort the rooms. Maybe you should think about making an appointment in advance so you can begin getting emotionally ready to let go of a lot of old stuff. It might be a bonding thing for you and the W to start piling stuff together. For everything one of your things in the pile, she has to contribut one of hers. Get the kids to match the donations somehow.