I'd be more worried about the 'trend' if it wasn't the polar opposite of what we were seeing in the preseason. Paul, Ray and Eddie were shooting the lights out in the preseason - all three of them were almost automatic from beyond the arc. In the face of that, its easier to see their struggles as more of a cold streak than any sort of imminent decline.
The only thing that really bothers me is the poor free throw shooting. Rondo's always been below average at the line, but Paul hasn't shot well either - and this, unlike the case above, has been going on since Game 1 of the preseason. The main problem here is that these are the two guys on our team that will spend the most time at the line this year. Refusing to take free points is a good way to lose games.