Will this lead to a flood of open source software for OS X?
Don't hold your breath.
Open source is big on Linux because Linux has significant server market share. People running server software gladly pay for support.
The speed with which Linux serves files and handles back-end tasks is superior, and its overhead is modest, so you have motivated buyers and a working business model.
In the PC world, there's enormous desktop market share and an important motive to develop open source tools -- namely to deny Microsoft incremental revenue. Besides, PCs have always been friendly to shareware and start-ups.
The Mac lacks these advantages. Ivan Krstic has made a MacBook his main laptop because it works, and he can afford the cost. It comes with most of what he needs, so "Hang me for treason."
But note that Krstic isn't rushing out to create open source software for the Mac. The installed base remains too small to deliver the support revenues necessary for success. And the Mac's own software bundle leaves few basic niches.
The only thing wrong with all this, of course, is that it might give Microsoft what I like to call a Clue. If Microsoft had shipped enough free software to make its machines useful, maybe open source would never have come to Windows in the first place.
But it's too late now.