Well let's wait and see. If the Wings get to the late rounds Bertuzzi will have made an impact, most likely (and hopefully not a criminal impact). Roberts has already made an impact, this year and beyond; with his Yoda-like teachings to the youngsters and showing the younger-older players (Malone types) the way of their type.
Foppa is a playoff player. It amazes me that people forget this. Let's not say anything about him until the playoff run is over, lest he make us look foolish.
I'd say several guys have, and could make impacts on their respective teams before the season ends.