Currently there is no ability to declare a preference for a release of a 
project.  For example, I'd like to say my project requires "a release of 
foo >= 2.0, <3.0".   I'd then like easy_install/setuptools 
to only pick releases (no qualifiers of any kind alpha, beta, dev, etc.) 
of 2.0, 2.1, 2.2, 2.3, 2.4, ....   As a further example, it should 
totally ignore '2.5a1' and '2.6_r15669' and instead would fetch '2.2' if it
existed in the same repository.

It would be nice if this was the default behavior unless the user specified an
additional flag to accept qualifiers(which would return the behavior to its
previous state).  Also, it would fall back on eggs with qualifiers if no
releases were found.