"Crying All The Way to the Bank:" Marketing Old Drugs by Combining Them With New Ones

From the NY Times, Pfizer has come up with a new scheme for marketing cholesterol lowering drugs.
The compnay is running clinical trials on a new drug, torcetrapib, that raises HDL ("good") cholesterol. Thus, the drug holds promise to offer benefits to patients beyond those from the traditional "statin" drugs, which lower LDL ("bad") cholesterol.
The trials apparently only involve a fixed combination of torcetrapib and Pfizer's statin drug, Lipitor. This suggests that Pfizer may only market the new drug in combination with Lipitor. Thus any patient who might benefit from the new drug would be forced to also take Lipitor instead of another statin (or a generic version of Lipitor, which will go off patent in 2010).
There is no reason to think that torcetrapib should work better with Lipitor than any other statin.
Thus the only obvious reason to offer only this fixed combination drug is to maintain the demand for brand-name Lipitor, according to Dr. Michael Crawford, a cardiologist at the University of California, San Francisco.
There are anti-trust laws that may ban companies from "tying" products together or refusing to sell one product without another. But it also seems that if the FDA were to accept Pfizer's application for a combined drug, this action would pre-empt an anti-trust complaint, according to the Times.
It may be a clever scheme to use one drug's novelty to maintain sales of another, older drug. But it clearly would restrict the choices open to doctors and patients, preventing some patients from getting drug combinations that might be cheaper, more effective, or less toxic for certain individuals.
As Dr. Crawford said, "It's an unfortunate decision on Pfizer's part. It's not going to sit well with people. But, you know, they're going to be just crying all the way to the bank."