As long as a CPU can offer excellent performance for sufficiently long term(4~5 years), the "future proof" doesn't really matter at all. The 860 is in this category.
I agree with you completely. I made another thread regarding buying a i7-9xx or waiting for Sandy Bridge and it seems to me that what you said must be true. If your getting such a high performing CPU now then there will not be a need to upgrade for most people during the life of the socket type.