I read that for the first time in decades the number of new drugs approved by the FDA was going to be fewer than the drugs going off patent (either 2009 or 2010 - I forget which).
I also read last year that the reason for the explosion in new drugs (something about breakthroughs in understanding of how certain chemicals reacted in the human body) that has lasted for several decades has pretty much exploited the "surface gold," so to speak. New drugs are going to be more expensive to find and develop, which means that new drugs are going to require more R&D to find and will likely be more expensive.
Another issue that has been raised is that many new drugs are either less effective or may, in some cases, be completely ineffective to treat the problems they were developed to fight. In some other cases, the drugs have such horrible side effects that the FDA has pulled some new drugs off the market.
The bottom line is that the years of finding easy winners and milking them appear to be drawing to a close. The future winners are going to be much harder to find and likely will take longer to find. Big Pharm may be in for further, significant down-sizing. Mini-Pharm?