I just wanted to update everyone on the list. The development of the wxPython next generation GUI for GRASS has been moving at a very fast pace. It now has much of the functionality of the current TclTk GUI, though it is not yet as robust and will certainly be more buggy.
All GRASS command and normal scripts are available—either through the menus (though these are still not complete) or the GIS Manager command line.
The GIS Manager layer tree work well, has groups, transparency, drag and drop, and layers for all major GRASS GIS data types. There is the potential for multiple map displays, controlled by a single GIS Manager panel, as we have now. But it’s a bit nicer and more modern looking.
The map displays have basic zooming, panning, querying, and saving to PNG. Map decorations (scales, legends, and text) are more easily placed and edited than in the current TclTk GUI.
The autogenerated dialogs for each GRASS command have a very nice layout and appearance.
There is a good beginning on an integrated attribute table editor. There is also a good beginning on a location creation wizard. We just need a non-interactive version of g.setproj 
or the ability to send g.setproj data (extents, resolution, and grass dataum and transformation names) to g.proj.
Major missing pieces are: special GUI versions of interactive x11 modules (i.e., georectification and profiling) and NVIZ. Direct printing does not work yet.
If you are interested in testing, the GUI files can be found at
https://grasssvn.itc.it/grasssvn/grassaddons/trunk/grassaddons/#_trunk_grassaddons_
Python 2.4 and above and wxPython 2.8 and above are required.
Enjoy
Michael
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics and Complexity
Arizona State University
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton