You need to look at the dropoffs by position, not by points. Yes, Johnson is less valueable in a PPR league, but you are also assuming that the top WR get the most receptions which is not always the case. Andre Johnson led the league in receptions last year, Mike Furrey was second, Steven Jackson and Reggie Bush were in the top 10 -- non of those guys would have been considered a top WR. 20 players topped 1000 yards in 2005, 19 in 2006; all of those players had between 69 and 103 receptions, and last year 41 players had over 60 receptions. So, a point per receptions makes all receivers more valueable, and slightl;y increases the value of an elite WR over a non-elite one, but does not negate the value of running backs.

After all of that, that scoring format does make a Steve Smith or Chad Johnson a more valuable player for you than Rudi Johnson. The problem with taking WR early is their touches are dependant on other players -- their QB and O-Line -- while a starting running back will almost always get 25+ touches per game. There is also a perceived value issue to consider. If everyone thingks WR will be more valuable in your league they will draft WR earlier than normal making RB a value.

So, now that I completely forgot my point, I would move WR who will catch a lot of passes up a few slots on my cheat sheet, move RB who catch a lot of passes up a few, and move down RB who do not catch passes down. Whether I take a WR in the first 2 rounds would depend on who was available. I would like to, but there are some decent WR who will be more valuable than normal -- Coles for example -- because they catch a lot of passes for not so many yards. I actually think that PPR makes for more WR values later in the draft.