Software code is not patentable, as many have asserted previously (pdf) and now we have additional confirmation of the U.S. Supreme Court's stance on the matter, via oral arguments in Microsoft v AT&T:

MR. OLSON [For Microsoft]: The '580 patent is a program, as I understand it, that's married to a computer, has to be married to a computer in order to be patented. JUSTICE SCALIA: You can't patent, you know, on-off, on-off code in the abstract, can you? MR. OLSON: That's correct, Justice Scalia. JUSTICE SCALIA: There needs to be a device. MR. OLSON: An idea or a principle, two plus two equals four can't be patented. It has to be put together with a machine and made into a usable device.

There are more quotes over at the Patently-O site regarding whether code can be patented on its own, check it out.