Not with screenshots like these.
http://images.gamersyde.com/gallery/public/7898/1316_0003.jpg
Notice the aliasing on the bridge pillars and railings, the shadowmap on the A-pillar? That is a true 1080p image. IMO it (the AA, if theres any at all) looks average and thats on a 19 monitor. When you blow that up to 46", its not exactly gonna help it get any cleaner.
Depends what you mean by "1080p support". All I'm saying is that since PD have openly said that GT5P will run in 1080p native, they have now commited to that as a baseline for performance. Sure in 720p it could have extra power to do more physics but they cant do that anymore since 1080p is the baseline which would use up that extra power when using the higher resolution.
Personally I would have preferred 720p native with 1080p support in the method of scaling. Its probably simply because I'm a sim junkie and appreaciate damage. They'll be others who feel the opposite and would rather have a nice pretty 1080p take priority over a more realistic racer. Its just a matter of personal taste, neither is wrong and in the end they are only opinions.
PD never said they'd support native 1080p. They don't even now.