Just rest your arm on your leg while you play.  Works perfectly fine for me; You probably do about the same thing when you play with a controller.

After watching the video I'm concerned about motion fidelity. I wrote a topic about fidelity to tracking distance. Devices that track from a stationary point(ie TV). Have fidelity issues based on distance. Closer something is the greater degree of motion is interpreted on movement with loss of easy accuracy. While being farther away require greater motion motion tracking with increased fidelity.

Watching the video of RE doesn't really do much to offer a lot of confidence on fidelity. Using the Wii Pointer fidelity is always on the users side of control and user wrist. Seeing the vid I noticed that the pointer at times didn't really move at all in any movement. While on the Wii it's not uncommon for it to shake over a tiny are due to the hand usual having micro movements. Is is possible then that the Arc lacks the fidelity of micro movement tracking. While this can be considered a good thing(since you don't want micro movement) the lack of ability to track it could just mean a lack of ability to be good at pointer tracking.

Finally. Serious. Are we really serious? Arc in one hand and a controller in the other? serious? Sony is going to alienate it's core fans with that.

No its not. I name myself Snake612 because Snake is the name of the main chracter in the Metal Gear Solid series and the 612 represents the month and day Metal Gear Solid 4 was released which is June 12 or 612.

Ahhh, so what you're saying is you are a fan of Metal Gear Solid then?