"Advanced file associations"

The new way of associating files with applications (Default Programs)
seem to be nice enough, but I miss one feature of the old way. Namely
the ability to add/remove items to the context menu you get when
right-clicking a file. There are some file-types that I'd like to open
with one application most of the time (60%) but quite often (35%) I'd
like to use another application instead.

Anyone knows how to change these things in Vista?

--
Erik Wikström