There's one drawback there, however... If you're stepping through the listcomp generation with a debugger, you won't be able to print the current item in the list, as (I believe) is possible now.
Good point. But this could be addressed in many ways; the debugger could grow a way to quote nonstandard variable names, or it could know about the name mapping, or we could use a different name-mangling scheme (e.g. prefix the original name with an underscore, and optionally append _1 or _2 etc. as needed to distinguish it from a real local with the same name). Or we could simply state this as a deficiency (I'm not sure I've ever needed to debug that situation).
--Guido van Rossum (home page: http://www.python.org/%7Eguido/)