Shapely 1.2.14 is up on PyPI: http://pypi.python.org/pypi/Shapely and the documentation has been updated: http://toblerity.github.com/shapely/. Mike Toews has made coordinate and (homogeneous) geometry sequences sliceable. For example, you can now get every other vertex of a line string or linear ring like this:
and a geometry collecting the odd points of another multi point geometry can be had like:
Heterogeneous geometry collections can't be sliced in 1.2.14. Down the road, maybe.