While I figured it'd be skewed more toward older stories, the 26 pieces collected are distributed fairly evenly among original publication dates, averaging a neat 1.5 stories from 1989-1998 (it literally alternates: 2 stories in 1989, 1 in 1990, 2 in 1991, 1 in 1992, and so on until the 1 story in 1998!), and then with an upward skew in the last three years: 3 from 1999 and 4 each from 2000 and 2001.
Of different publications represented, YARF! is tied with PawPrints at 3 stories apiece, with Anthrolations, FNC and Fang, Claw and Steel at 2. If you count the three incarnations of Mythagoras together, it's also at 3 stories apiece (one from each iteration). Only one story whose original publication was on the web was chosen.
While this obviously represents editor Fred Patten's various biases, he did a better job than I probably would have in finding things across the spectrum, both in terms of year and of source. Tuftears wrote, "I suspect people tend to remember the first things they read more than later things," which would have certainly been true in my case, and I'm not as up on what's happened in the fannish print world post-1995 as I probably should be.
I can't really say the distribution of the source material surprises me, though--YARF! has had about five times as many issues as anything else represented (save Rowrbrazzle), and I suspect PawPrints, Mythagoras and Anthrolations have had the most rigorous editorial standards of various furry-esque publications over the years. Prozines account for a slightly disproportionate number of the stories collected.
If the "Ursa Major" awards truly take off, I'll be curious to see if this trend holds true. My suspicion is that the best stories will increasingly be in prozines, as YARF!'s publication schedule has been cut in half and Sofawolf and United Publications seem to be ramping up their own production.
The question is, though, how many of those stories will actually end up in front of fans whose primary exposure to "furrydom" is through the internet? Many of them haven't seen print fanzines, and some younger ones seem to have that "the web makes 'old media' irrelevant" attitude that pretends editorial standards are also irrelevant. And I suspect many of them have no idea furry fandom is approaching its twentieth birthday. This, though, is a rant for another time (if it happens, I'll try to keep the old fogie "in my day, we had to walk through the snow five miles barefoot to get our comics" cane-waving to a minimum).