If you are planning to use Isolated shell, you can't use Microsoft Language Packages like C# and VB.NET inside that.
Creating a package for your shell is much like creating any other VS Package.
You don't have support for Team Explorer and VS Built in Source Control access, in Isolated Shell
Also, you if you are using VS SDK 1.1 to develop your packages - remember that the managed package framework is no longer available with the default distribution. So don't get surprised if your old packages can't load MPF files after moving to SDK 1.1. It has got moved to Codeplex as a separate download.