I've implemented last night's design, in debhelper 7.0.0.

Currently fully supported are packages that use the autotools, or perl's MakeMaker, or python setup.py, or a simple Makefile. The other classes of packages will be added as bugs are filed about them.

I've uploaded a few of my own packages converted to use debhelper 7 with minimised rules files, so there are a range of examples in incoming:

Early adopters, have at it!