I have just got a MacBook Pro and have been using it (+Fusion) to develop on for about a month now. The purpose of this question is similar to Hidden Features of C#; to become
Oded, it depends on what type of .NET development one is trying to do, and for what platform. If you're targeting Windows and building something other than console apps, you're best off not using Mono, as Mono projects are not necessarily drop-in-to-Windows-and-go solutions.