Yep.Interestingly, this does pixel count as 1920x1080--but the interlacing artifacts are there too (though very mild). It might be a bullshot, but another possibility is that the temporal effect achieves better results with less camera motion. Maybe in certain circumstances the resolution truly is almost indistinguishable from native...only in MP, you're basically never going to be sitting still. Just a guess.
The quality depends on reprojection. Some PS360 games did temporal antialiasing with no motion reprojection at all, which meant that they suffered from ghosting if they didn't turn off blending for areas of the screen that were in motion. You can see this in Halo: Reach, where AA turns off during motion, and ghosting happens in some cases where (usually animated?) dynamic objects don't contribute correctly to the motion buffer.