The Debugger plugin interfaces with the GNU GDB and MS CDB debuggers, providing a graphical interface to these command-line tools.
Currently, the debugger branch (wxpropgrid_debugger) contains significantly improved debugging capabilities. See the nightly builds to download a recent version.
2012-04-07, as of rev7920, the debugger branch was merged to trunk, so all the new debugger plugin features is now in trunk.
The next generation of debugger plugin will use the GDB-MI interface, and it is under developement, but it is at least usable. You can try it. see GDB-MI Plugin.