>How many people with 2.8VRII upgrade to >a VRIII? Enough to make it profitable to install the new >technology in the same lens. Look for the VRIII in an updated >AF-S 80-400 that everyone is waiting for.
I frankly wonder how many people went for the VR-II versions as a real percentage. I know some did (they said so here), but I also know a lot who say the 70-200 and 200-400 VR-II versions did not make enough of a difference to change. I'm in that boat as well.
I imagine the marketing guys trying to optimize their product mix vs. profit don't see single-version upgrade as the main part of their sales, but rather are going for upgrades from lower lines or P&S's, moves from other products, etc.
I'd personally upgrade faster for fast (e.g. a 70-200/F2) than for better VR. Not that I don't love VR. I'd also take a 24-70 VR in a minute if it was equally sharp and F2.8, even if it were heavier.
But VR-I to VR-II wasn't noticable to me (I have one). Maybe VR-III will be. But I'd wager that people doing upgrades are not their market.