^ Wouldn't that basically imply that phasers are subluminal, speed-wise? Otherwise the phaser "bolt" would pretty much arrive at the same time as the pointer, so I don't think it would be all that beneficial.
Then again, I may be wrong -- dang relativity!!
Was it mentioned up-thread that this (supposed) arcing could be artifacts from the 3D conversion process? Even in 2D (best way to see STID, IMO), you could tell where there was a "3D type" scene (like the "warp trails", etc.), as it would skew things visually.