Samuel is as good as he was before, after the game against Fiorentina I have no doubts someone gave him a kick up the ass. The problem (well not really a problem) is in the form of his life and has momentum through the scales and cannot be dropped.
Samuel and Materazzi should be the partnership for matches against technical sides, anyteam that has a pacy and quick striker then one needs to be dropped, no doubting that, and that means that Samuel-Matrix should be the partnership atleast 75% of the time, they only struggle against quick, fast paced passes (i.e Roma)...and I think that game was over read, it was the first game of the season.
In the perspective of Materazzi, his best partner is Burdisso. That would be extraordinary.