Lightsaber fighting styles

It really depends on the movie. Episode IV they were using a kendo style of swordfighting, hence the fight between Obi-Wan and Vader. Episode V was geared to be a little less stiff, as you had the youthful Luke battling Vader - by the way Vader's style is primarily Djem So, with some other forms worked in. Luke mirrors this, and so you see the two fighters using strong aggressive attacks and counterattacks. When you see him start using one hand, it's a visual hint to suggest that he's toying with Luke, not using his full power. By the end of the fight he's going nearly all out, with vicious two handed swings. Episode VI had the same kind of Djem So combat - you can REALLY see Djem So at full power when Luke goes ballistic against Vader in the end.

When they started making the prequels, Lucas wanted some amped up fights since these were supposed to be Jedi in their prime - so you get some of the other fancy forms like Ataru and Vaapad. The form that was based on fencing the most was Makashi, which is what Dooku is supposedly a master of (I say supposedly because his fights in Episode II were just terrible).

You're right though, Bob Anderson was indeed a fencer. In fact, he was the Swordmaster for several well-known movies (Mask of Zorro, Princess Bride). I was just remarking that the OT used mostly elements of Kendo and Longsword in their lightsaber choreo.