I think the pixel orbiter is just there to make people feel better. To me it doesn't seem to do much. It only shifts the image slightly, a small number of pixels worth, so rather than prevent burn in or image retention it will just blur the edges of a burned in image. I leave my Panasonic in THX mode which completely disables the pixel orbiter feature and haven't had a problem. Then again, I don't game or use the TV as a monitor. I'd say just be aware of your usage, and running some full-screen content with a lot of action after a gaming session will do more to prevent IR than a pixel shift feature.
ht Panasonic TC-P60ZT60, Monitor Audio: Silver RX6, RX Centre, Radius 90HD; Martinlogan Dynamo 700, Marantz SR5006, PS3, Oppo BDP-103D
2ch Marantz PM8004, Sony BDP-S1000ES, JVC T-X3 tuner, Monitor Audio Silver RX1, REL T3, Apple TV, Peachtree Audio DAC•iT
lr Panasonic 50ST60, Sony BDP-S5100