I believe what Cameron has stated is that he used to prefer full frame transfers for home video back when all displays were 4:3. Stanley Kubrick cited similar preferences, which I read was due to how awful 2001 looked when it was panned and scanned. That's why everything he did after that was shot on Academy ratio stock and was composed not only to look good for matted theater showings, but also look good on home displays with the full frame in view. Now that the majority of displays sold are widescreen, I'm guessing both directors would have different opinions on the matter.

While the full frame transfers of Kubrick's later films are quite nice, I'd like to see a future release (possibly in HD on BluRay) that has both a full frame version in keeping with Kubrick's last known wishes and a matted, anamorphic transfer that reproduces their original theatrical aspect ratios.