Don forwards some particularly interesting observations with spoilers about a scene described from Episode II, and a connection to the Classic Trilogy:

I was reading through some of the articles on TFN, in particular the one on "Stuff around the Web" (here)about how Dooku fits in. I remeber on the posting from the other day about the Master Replicas lightsabers it had a quote from Dooku "As you can see, my Jedi powers are far beyond yours." I really didn't think too much of it until I read the post about how Dooku fits in.

If Yoda was his master or he was initially trained by Yoda then perhaps he says this line to Yoda. We all know that Lucas has recurring themes throught the SW movies. This particular theme of the student vs the master seems to be a reccuring one. Obi-Wan vs Vader, Anakin vs Obi-Wan, now Dooku vs Yoda. Even the line from "A New Hope" is similar to the one from Dooku in AOTC. Vader: "When I left you, I was but the learner; now I am the master." Dooku: "As you can see, my Jedi powers are far beyond yours."

Lucas I believe also said we'll see why Yoda is the master in AOTC. No doubt he is referring to this fight.

We certainly hope that is how the line fits in, though there are several people involved in that scene, so it could be any of them.

UPDATE
Andrew adds this, which still leaves the cool connection to the Classic Trilogy:

In response to the Move from Master to Learner article, below the Dooku quote on the prop catalog, it says (spoiler) Dooku to Obi-Wan, so he couldn't be saying it to Yoda.