There are still things in Visual Studio as of 2013 that are available for C# but not for VB, not that you can't do it in VB. One that I ran across recently was there wasn't a "Debugger Visualizer" template for VB. The debugger visualizer template basically gives you the bones of what you need to add if you were going to add a visualizer into Visual Studio.
There are two references you'll need to do for the below code to work.
Here is a conversion in VB of a DialogDebuggerVisualizer (for a String) that I made from a C# source template that was working.
<Assembly: System.Diagnostics.DebuggerVisualizer(GetType(CharVisualizer), GetType(VisualizerObjectSource), Target:=GetType(System.String), Description:="Character Visualizer")>
Public Class CharVisualizer
Protected Overrides Sub Show(windowService As IDialogVisualizerService, objectProvider As IVisualizerObjectProvider)
If windowService Is Nothing Then
Throw New ArgumentNullException("windowService")
If objectProvider Is Nothing Then
Throw New ArgumentNullException("objectProvider")
' Get the item as a string (in our case, this would be whatever data type you're dealing with)
Dim data As String = objectProvider.GetObject.ToString
' Show the data (or a form, or whatever you want to do)
Public Shared Sub TestShowVisualizer(objectToVisualize As Object)
' This is shared so that it can be called with instantiating this class.
Dim visualizerHost As New VisualizerDevelopmentHost(objectToVisualize, GetType(CharVisualizer))