I think including source code in patents would (a) achieve the goal of creating a public good, and (b) provide a concrete mechanism for gauging prior art and obviousness. We already have tools for detecting plagiarism in computer science assignments.

Of course a patent application could include obfuscated code, but if the obfuscation were effective then it would be unenforceable -- oh the irony. (my new implementation is much more efficient...)

I agree with your points, but I don't see that they actually detract from what I propose relative to the status quo.