Great, now fix all the problems in Xamarin!
This is great news as long as they roll up their sleeves and get fixing stuff fast. Xamarin as a concept is great, but there are a number of problems especially in forms.
Speed, more speed! The layout seems crazy slow right now.
A deterministic layout engine would be nice on Android. You can have a layout that works 3 out of 4 times. It's exactly the same code and data, but the fourth time you visit the page, it lays out differently. This seems to be especially true of text labels - WTF? How do you even go about creating a bug like that?
Layouts in forms, generally suck. Padding doesn't work the same on iOS as android, Grid layouts are particularly unpredictable. Nesting layouts (which you inevitably have to do) can produce unexpected layout issues.
Intellisense support for Xamarin forms XAML. It's basically unusable right now. We write everything in code, as we get intellisense support there, and with the long compile / install times you cannot afford the hit/miss nature of writing XAML without intellisense.
Create a decent paging system for Xamarin Forms, the existing ones sucks bad. When you change from one page to the next, everything visibly blanks/redraws and generally looks very unprofessional.
We are looking at binning theirs and creating our own in-page solution.
MORE SPEED!
Generally, writing in C# in visual studio for mobile is a great experience, but there's enough problems right now that it's not the slam-dunk obvious recommendation that it should be.
Did I mention speed?
Stop the debugger failing to connect about 25% of the time, and the app crash on startup with a debugger about 10% of the time (with android).
Fix the use of partial classes - you get a weird bug where it sometimes can't hit breakpoints in code that's split across two files (haven't seen this for a week or so, so it may be fixed).
Fix the fast deploy system for android so that it doesn't miss changes you make and consequently waste half your day hunting for problems that don't exist!
Really hope they fix all this, as writing mobile apps in C# is a whole better experience than either Java or JavaScript+HTML in my experience.