Woooooooohooo!
I have been spending the past month getting ramped up for Xamarin.Forms and have been spending a LOT of time trying to solve the tricky problem of aspect-oriented-programming for Xamarin libraries. It is a problem because it involves dynamic code, which is a no-no on Apple's platform. I ended up (begrudgingly) on T4 templates, which, if you have ever used them, feel like they have been developed by an army of interns.
Anyways, I just found out that PostSharp has just introduced support for Xamarin libraries!!!
http://www.postsharp.net/blog/post/Announcing-PostSharp-41-Preview-4-Xamarin-Support-and-More
This means AOP for Xamarin!!! Such very good news. I am a happy codin' monkey right now. 
Just had to share!