For me, De Jong is one of the first names on the team sheet, his role is invaluable and he's one of the better ones around atm, head and shoulders above Mascherano, another league to Scholes and Anderson, surpassed Essien at our palce this season, a different planet to Song and Denilson... then there's Palacios, Reo Coker, Felani.
All teams at the top of the league seem to employ a DM nowadays, even Bolton (Muamba), Blackburn (N'Zonzi), Sunderland to an extent (Cattermole).
Go a little further, Goals this season by De Jong's counterparts:
Mascherano: G:0 A:1
Essien: G:3 A:0
Mikel: G:0 A:0
Anderson: G:1 A:2
Scholes: G:1 A:4
Song: G:1 A:1
Denilson: G:3 A:1
Muamba: G:0 A:0
The one's that tend to play an identical role to De Jong: namely Mascherano, Muamba & Mikel have a total of 0 goals and 1 assist between them this season. Denilson and Essien who have both played a further forward role at times this season haven't scored more than 3 goals and Scholes is by far the most prolific in assists with a mighty 4.
What i'm trying to say is; De Jong's role isn't to score and create goals, and i can never understand why, when we're winning, he's great and when we're not he should be benched, unbalance the side just so we can squeeze another goalscorer on the pitch.
If Adebayor, Tevez, SWP, Bellamy can't score goals then we're in trouble. With Johnson, Petrov, Ireland, RSC and Barry in the frame as well, we really don't need to be scrutinising our defensive players for more goals.