actually, i'm trying to build such a thing myself.
with python + QT.
the main problem i face is memory consumption:
python + qt + small-gui-app = consume most of the free memory on the machine( slc-860!), i.e., 50-60% ram, which is WAY too much if you like to multi-process.
maybe i'm doing something wrong.
i'll try to post the code somewhere. in the mean time, if you want my source-codes (it's far from being operational) - just contact me.