With its pending acquisition of Wyeth ( WYE) for some $68 billion in cash and stock, Pfizer ( PFE) is looking a bit like the pharmaceutical equivalent of the New York Yankees. A big-market, wealthy team, the Yankees haven't won a World Series since 2000. In trying to recapture past glory, they have invested heavily in veterans and youngsters alike who frequently failed to live up to expectations. For Pfizer, instead of a roster filled with aging players with diminishing skills, the drugmaker has an aging pipeline with a roster of former stars that have lost patent protection or will lose exclusivity in the near future. Internal R&D and collaborations haven't produced enough big winners, and Pfizer certainly hasn't been able to match the success it has had with Lipitor. Lipitor, a cholesterol drug that is the world's top-selling medication, was acquired in the blockbuster acquisition of Warner-Lambert, which just happened to be the same year as the Yankees' last World Series victory. The approaching trouble is that Lipitor loses U.S. patent protection in late 2011, taking out 26% of corporate sales. Lipitor produced $12.4 billion in sales last year, down 2% from 2007. For several years, generic competitors have been eating into sales of former Pfizer hits such as the blood pressure drug Norvasc, the cancer drug Camptosar, the allergy drug Zyrtec and the antidepressant Zoloft. At the same time, Pfizer has endured disappointments with failed products -- the inhaled insulin Exubera and experimental compounds, most notably the cholesterol drug torcetrapib, come to mind. What Wyeth brings is a roster mixed with solid performers, untested products, aging drugs nearing patent expiration and assorted role players that will probably be shed. The question is whether Wyeth in the end offers enough to help Pfizer get back to championship form. Investors didn't appear to have much faith that that would be the case, at least in the early going. Shares of Pfizer fell 10.3% to $15.65, while Wyeth edged down 0.8% to $43.39 after spending much of the session in positive territory.