Question: What are some key bindings that aren't included?

Answer: 
Here is a link of the assemblies that it ships with: <http://docs.xamarin.com/ios/about/assemblies>

Here is a summary of the .Net framework assemblies:

> 
> **mscorlib.dll**  
> 
> *Silverlight, plus several .NET 4.0 types*
> 
> 
> **System.dll**  
> 
> *Silverlight, plus types from the following namespaces:*  
> 
> System.Collections.Specialized  
> 
> System.ComponentModel  
> 
> System.ComponentModel.Design  
> 
> System.Diagnostics  
> 
> System.IO.Compression  
> 
> System.Net  
> 
> System.Net.Cache  
> 
> System.Net.Mail  
> 
> System.Net.Mime  
> 
> System.Net.NetworkInformation  
> 
> System.Net.Security  
> 
> System.Net.Sockets  
> 
> System.Security.Authentication  
> 
> System.Security.Cryptography  
> 
> System.Timers
> 
> 
> **System.Core.dll  
> 
> System.Data.dll  
> 
> System.Data.Services.Client.dll  
> 
> System.Json.dll  
> 
> System.Numerics.dll  
> 
> System.Runtime.Serialization.dll  
> 
> System.ServiceModel.dll  
> 
> System.ServiceModel.Web.dll  
> 
> System.Transactions.dll  
> 
> System.Web.Services  
> 
> System.Xml.dll  
> 
> System.Xml.Linq.dll**
> 
> 
>
One thing to also mention is you cannot reference .NET assemblies that haven't been built/compiled using the .NET MonoTouch configuration.

So if you have a favourite .NET 2.0 library you will need to re-import the source into a new MonoTouch project, compile it, and then reference it. There may be an easier way of doing this by editing the `.csproj` file but I haven't found it.