I like all the fun of conspiracy theories, but I don't think there is any hidden agenda behind SB's words. It is not hard to observe that Apple's Store is successful model that will encourage developers to develop for the platform and boost platform's popularity in the process... well, short of Apple's censorship here and there, but that is obviously not making any significant impact - if any impact at all.
So good old SB sees good solution that is not copyrighted and is interested to apply it to his new babies. Big deal.
As long as conspiracy theory goes, since Android penetration isn't that strong, it might turn out that MS with WP7 will be stronger competitor than Google is. They will also have multiple brands behind their platform and, if Apple beats HTC regarding patents infringement (and maybe others to follow), some of those brands might end up Windows only; I think it is safe to say that WP7 looks significantly different to iPhone OS than Android, and at least some of infringement claims cannot be applied to it.
Additionally, there is a chance that MS Courier will see the light - according to this article, http://www.dailytech.com/article.aspx?newsid=17838
, device could come out Q3 or Q4 this year, will be based on Tegra 2 and WP7... which sounds about right. And again, Android tablets seem to be copying iPad with some extra features and potentially lower pricing, while MS is trying to accomplish different kind of experience. If they manage to do it right - yes, big if - whole WP7 platform with Zune HD, Zune Phone and Zune Booklet (Courier) could be as strong player as Android.
So what would actually be Apple's interest to cut ties with one, at least known, enemy-in-bed and jump into another bed where still unknown enemy lies..? Particularly that Google, no matter how big, still is freelancer, while MS is heavily involved with other enemies of Apple - PC manufacturers..?