Short Answer:

NO - Microsoft won't give you any official support.

GS2.0 has been confirmed to work on all Visual Studio SKUs Microsoft have stated that only c# will be officially supported and only C# within VS will have the IDE enhancements for XNA GS.

GS3.0 - nothing has been announced about other language support at this time see GS3.0 FAQ

Medium Answer:

Not fully - see the Visual Studio FAQ for more details http://forums.xna.com/7263/ShowThread.aspx#7263. You can reference the libraries but you won't get starter kits, content pipeline or Xbox deployment and debugging.

Long Answer... aka if you really must try and you understand the above restrictions:

• C++/CLI
  Works as long as you compile using the /safe flag (/pure is not enough)
• Visual Basic.Net
  emachine has a VB.Net template for XNA 2.0
  Alan Phipps is using XNA with Visual Basic 2005 - check out his blog http://www.alanphipps.com/VisualBasicdotNET-XNA.html.
  See this thread for GS 2.0 templates and even content building from emachine
  Visual Basic has several libraries that will not work on the Xbox e.g. the My namespace.
  Chris Williams has a blog on using GS 2.0 with VB The VB XNA project
• F#
  There are several people working with F# http://www.google.com/search?q=XNA+F%23
• Chrome (Pascal)
  Somersault is working with a Pascal derivative called Chrome from http://www.RemObjects.com. Some information here
• LUA - see the XNUA page
• IronPython won't work on the 360 because it relies on Reflection.Emit which is not available. (This article implies otherwise but we have no evidence to understand how)

Deploying to the xbox can be performed using the .ccgame packaging command line tools which require a GS install to obtain.

Building content can be done using a C# project just for content or using command line MSBuild both of which require a GS install and cannot be done using the XNA redist.

360 potential issues

Other languages may or may not work on the 360 depending on how they compile things. The compact framework does not support all of the IL instructions that the full framework does (see http://forums.xna.com/thread/13402.aspx) so your particular compiler may produce code that will not run. Some parts of System.Reflection (reflection.emit for example) are not available on the 360 either which rules out any languages that rely on those. In addition some languages such as VB.Net come with additional libraries (e.g. the My. namespace). Since these libraries don't exist on the compact framework apps that rely on them will not run on the 360.