While Visual Studio .NET 2002/2003 use their own font setting for dialogs and toolwindows, Visual Studio 2005 and higher honor the system font, which in Windows Vista is no longer the Tahoma 8.25pt of Windows XP or Windows 2000. See how to do it in your own add-in with my latest article:
HOWTO: Use the system font in dialogs and toolwindows of a Visual Studio add-in
http://www.mztools.com/articles/2007/MZ2007030.aspx