A recurring topic these days: to customize Project Professional 2007 should I be using VBA or VSTO?
Jack Dahlgren has just published a great post on the subject: Making the move from VBA to VSTO in Microsoft Project highlighting two benefits of switching to VSTO:
ClickOnce deployment allows you to publish Windows-based applications to a Web server or network file share for simplified installation. Visual Studio provides full support for publishing and updating applications deployed with ClickOnce.
Other interesting articles worth reading on pros/cons of making the transition are: