According to this news article, Roche claims that new batches of Tamiflu started this week will take a year to produce. The article doesn't say it explicitly, but I'm sure that the one year claim is including the waiting time caused by shortages of ingredients from suppliers, too. The article gives a glimpse of how complicated it is to make Tamiflu. (Many other medications are probably just as complicated and the public just has no clue either. It's like not appreciating where your food comes from.)

The FDA requires very stringent documentation, testing, and inspections whenever you alter your usual manufacturing process, like trying to ramp up prodcution, including all your suppliers and subcontractors, so that also delays the whole process. The pharmaceutical manufacturing business is a HIGHLY regulated industry and nothing happens quickly.

Anyway, just another "Greater Good" reason not to try and hoard Tamiflu while governments are still trying to stock up.

Hoarding is one thing, but ordering it will increase the demand which down the
road will increase supply. Every one should buy some and get a flu shot each year as well to keep the manufacturers able to deliver large quantities. Much of Europe
already has orders in for Tamiflu to cover at least half their population. The US has about 2%. And Europe ordered first.