> According to Wikipedia: User can send his bitcoins on this service, pay small commission, and then receive the same sum of utterly different bitcoins.

If they're paid out to one address it still wouldn't provide the desired level of anonymity, if however they are paid out to multiple addresses belonging to the same user, I would imagine the anonymity level would increase but not totally since one could still add up payments made to different addresses whose total should amount to a given range.