Renoise’s disk browser already features a ‘preview of samples’. My suggestion is that the user has this option also in regard to songs.
Maybe something like (somewhere in the Preferences menu):
We can already do this today, by unfolding the [+] to the left on the song’s name and then clicking on the samples. This is just a more convenient way to let the user quickly browse his songs and preview them (given that he has saved a rendered selection as a sample, and placed it on the first or the last instrument slot before saving the .xrns, of course).
See also: Fast Preview Of Songs in the Tips & Tricks forum.