I just wanted to send some constructive feedback about getting started with the product. I want to preface that I think the product is absolute magic and you guys are doing a top-notch job. With that, here are two critiques:
Getting started with the Hello World tutorial was frustrating. First - there was enough outdated information in the tutorial to cause confusion. Second - and this is really the source of most of the frustration - XCode wasn't interacting correctly with MonoDevelop on first run. I did follow the setup instructions but I think MonoDevelop was disconnected from XCode for 1 or 2 reasons: either it was because I had MonoDevelop running before the XCode install had finished (it takes a long time and I'm too impatient ... I wanna play with the new toys!) and / or it was XCode's first run so a license agreement was unknowingly getting in the way (both scenarios were in play but I'm not sure if it was one, the other, or both causing problems). Whatever the case was, clicking on the xib was not launching XCode. So I did a right-click > open with (as noted in the tutorial) and opened the xib. However, even though IB was open with the xib, the XCode project files - and most importantly the header file - weren't automatically generated. Being completely unfamiliar with XCode I fumbled around for about an hour trying to manually create header files, drag & drop outlets, etc. with no joy. It wasn't until I finally closed everything down and started the tutorial anew did things work properly.
Creating an account at Xamarin causes you to return to auth.xamarin.com after email verification. Here you're presented with a blank page with no further instruction. I then manually hacked the URL from https://auth.xamarin.com to https://xamarin.com at which point it 404'd. Eventually I returned to non-SSL xamarin.com but now I had to log on again before I was finally able to write this post.
I want to stress these are minor quibbles compared to the awesomeness of Monotouch. But with these "onboarding" issues ironed out, I think you'll be that much closer to truly "delighting" your customers.
Thanks for a great product! I hope this post is helpful.