I'm in the same situation, except I downloaded (readily available if you know where to look) Vista installation media as I felt the need to have an installation disk handy in order to be able to do repair installs and startup repairs.
Anyway, at the very least, the dual install W7 method (clean install W7 w/o key, then do an upgrade install from w/i the newly installed but unactivated w7 w/ a valid W7 key) should work for people who don't have Vista installation media, as was already explained in several recent threads. If that turns out to be true then I don't see this upgrade process as being a problem or sucking, in any respect.
I, for one, would gladly suffer the inconvenience of having to install W7 twice in a row (an extra hour or so of time) to save the amount of money one can save by purchasing a discounted upgrade version instead of the full version and appreciate MS making this money saving method of obtaining a legal copy of W7 available.