You should consider the following questions when making decisions for migrating existing COM content to .NET:
Do I have access to VB6, VC++, or Visual Studio in which to develop?
Does the symbol need to run in a 64 bit version of the application yet?
Are there features of .NET or the new 3D API in which I need to take advantage?
If some or all of the above are requirements, then you should consider migrating the symbol to .NET.
This following section provides guidelines on how to migrate an existing symbol to .NET.