registering for the expensive crap is a good idea, most places that do a registry will give you X% off to complete the registry after your wedding/shower/whatever, plus a lot of people give gift cards to the places you register, so win-win.
i agree with only register for crap you want, and don't go overboard. We (no, I didn't marry myself as suggested) didn't register for much cause we didn't need it-being elite working professionals, we had most stuff we wanted

-we registered for china, nice(ish) silverware, everyday dishes and nice cookware and that was about it.