The cast was the best thing about the trilogy. Ewan McGregor, Liam Neeson, Natalie Portman, Samuel L Jackson, Jimmy Smits...the cast reads like a who's-who of the acting elite of the early 21st century. And Hayden Christenson, unconvincing as he often is in the films, is a terrific actor--one has to only look to his other work, which is consistently of high quality. Portman too is completely stilted and unconvincing in the PT--using these films as a point of reference, one would have to conclude that she should have never got into acting in the first place. Until you look outside the PT and realise the astounding talent she displays--Cold Mountain, Leon, Closer, etc.
The cast was absolutely first rate, especially when you add Ian McDiarmid and Pernilla August to the mix, underrated actors that are mostly of the stage background (for other instances of August one has to look no further than Ingmar Bergman's many wonderful plays and films).

If you have a cast as talented as that, one which outshines in pure talent and range such star-studded actor-vehicles such as Ocean's Eleven, how can you possibly, concievable do any wrong? What is most incredible is not that the PT wasn't a film which theater students should have studied, not that it didn't manage to garner any acting nominations at the Oscars or any other awards shows, but that the actors on display were so consistently poor in performance. Now, some of them are quite adequet, and in a few rare instances they actually impress, but when you consider the potential that lay in there it is a crime of galactic preportions that the PT had such tame and unremarkable performances.

How can anyone suggest that the cast was inadequet? On the contrary, i can hardly think of anyone to add. Thus, you see where the problem lies. Leave the cast alone--get a new director. If this is what Lucas can produce when he has such sickening levels of talent surrounding him i would hate to think he would have done had he not been supported by such generosity. Any director would kill for the cast Lucas recieved. One only needs to compare Natalie Portman's performances in Attack of the Clones and Closer--the actress is the same, but in one she is so bad that i often laugh out loud in embarrasment, and in another she is so captivating that i become lost in the illusion that she is not actually the person she is depicting onscreen.