Yes, the conditioning is going to happen whether it's kegged or bottled. The carbonation is also going to happen, whether sugar primed or forced. But the residual yeast in all my kegs is inactive because of the temperature. There's trub at the very bottom of the keg when I clean out the empty ones. I don't filter or pasteurize my homebrew, so it's to be expected.
As far as extended shelf life..... I drink my kegs dry too quickly to have any reasonable answer to that.
In another month, I'm going to tap into the keg of Amber Lager, and I expect it to be really primo after sitting there since Christmas. Cold is a pretty good preservative.
