It's a little tougher than this article makes it sound. iPS cannot do everything that embryonic stem cells can do, and he cited a paper that has been retracted: http://news.sciencemag.org/scienceinsider/2009/07/journal-ed...

(bottom line - the "sperm" created for iPS don't really work as such)

It's still probably coming eventually. And why stop there? Polyamorous n-tuples could have a kid who was a mix of varying proportions of the parents.