I haven't poked much at Yuletide, but there are two that I can recommend to anyone at all familiar with their canons:
The most perfect companion to Pratchett's _Nation_ that I can imagine,
The Light Always Burning. Just astonishing; the voice is dead on, and the content fills in the future history of the Nation in the most believable and satisfying way possible.
And if you are still mourning Glitch,
Imagine a World With No Pants will give you something to laugh about through the tears. Also perfectly true to the voice and spirit of the place.