Genetically-modified yeast strains are currently being used to make all kinds of compounds. An injectable insulin analog called Levemir is made by yeast cells that have been modified using recombinant DNA technology. Levemir is made the by same company that acquired the old Wallerstein Company (successor to Wallerstein Labs) from Baxter Labs in a litigation battle in the seventies; namely, Novo Nordisk (the business unit of Novo Nordisk that acquired Wallerstein was known as Novo Terapeutisk in the seventies).
Wallerstein Labs was the premier brewing science organization in the United States at one point in time. WLN (Wallerstein Labs Nutrient Medium) and WLD (Wallerstein Labs Differential Media) are still the most popular media in use in brewery quality control labs around the world. Anchor's Steam strain was acquired from Wallerstein in the mid-seventies (i.e., Wyeast 2112 is not an heirloom steam strain). The New Albion strain is also a Wallerstein strain.
Novo Nordisk uses S. cerevesiae to make their whole line of insulin products, not just Levemir. Sacc is also used for many hormones (HGH, glucagon, GM-CSF, etc) as well as some vaccines (Hep B and Gardasil are the ones I'm aware of).
What is most interesting to me is that they are cooking up a cheap, readily available drug. Most recombinant DNA based drugs are typically peptides (long strings of amino acids) that are well-suited to this kind of technology. Other natural products are a lot more challenging, because it's not generally as simple as 1 gene=1 peptide. It will be interesting to see if this kind of bioreactor scales up economically.