VBA (internal to support an application) and VB/VB.NET (external) have
different strengths so it depends on what you are trying to do. There has
been no announcements relative to a replacement of VBA. The latest version
of VS2005 has an office addon, but does not include Visio. The next version
of Office (visio included) is just beginning it's alpha testing and VBA is
still there. Heavy duty development of Visio apps is more and more going
towards .Net solutions
Al