Thanks, Neuro! That is definitely a precise and comprehensive answer.
I had seen promo codes under the Deals postings on Digital Picture but had not seen this rebate tracking list.
It looks like they never go more than 2 -3 months without a rebate running, which does help douse the sense of urgency.
Rebates aside, though, if I had a nice canon refurb promo code (that was working), I think I'd warm up the visa card tonight anyway.