Both teams in the World Series--Chicago and Houston--have three potentially dominant starting pitchers. Chicago has Contreras, Buehrle, and Garland, and Houston has Clemens, Pettitte, and Oswalt. This isn't surprising given that most teams that make it to the World Series have great starting pitching.
What does this mean for the Nationals? We have one starting pitcher--John Patterson--who was dominant last year, but who now must prove that he can be this good year after year. We have another pitcher--Esteban Loaiza--who outperformed all expectations, but who has been inconsistent over time and is not likely to be a very good starting pitcher (at least on a consistent basis) outside of RFK. A third starter--Livan Hernandez--was very good in the first half, but isn't a dominant pitcher mostly because he can't throw a fastball over 85 mph and has thrown so many innings that his arm is likely to fall off any day now.
Patterson would slot very well as a #2 starter, and Loaiza or Hernandez would be good #3 starters and very good #4 starters. What the Nationals lack is a dominant starter who could catapult the 1-3 slots into the upper echelon of rotations.
Yes, I know, the Nationals pitching stats last year were great, but a lot of that was due to the run depressing effects of RFK. And late in the season the Nationals' rotation wasn't good enough to dominate games when we really needed it. If we're trying to build a team that can compete effectively in the playoffs, we need better starting pitching.
So, we need a dominant starter. Is there anyone like that available? Yes--A.J. Burnett. There is a lot of skepticism among Nats fans about Burnett, but he's the best pitcher available, and he has electric stuff. He had a falling out in Florida, but so did most everyone else. If we want to upgrade our starting rotation, going after Burnett could fit the bill.