GstarCAD revealed this morning that it is is developing GstarCAD M -- the M is short for "mobile" -- for viewing and editing DWG files on the iPad. Not a lot more detail available, except that this is a great time to release such software, as the press release puts it:
With the advent of vehicles, variety delicious food as well as internet, etc., people’s lives become more and more colorful. Now with iPad came into being, the applications running on it is inevitable, for the work efficiency improvement turns into urgent, among which CAD software bears the brunt and GstarCAD M emerges as the time requires.
There are quite a few DWG and DXF viewers available on iPad, but no native DWG-file editors yet.