While I look forward to seeing many of the old articles updated, I think that the best of the advice for players and DMs can be a great help. A lot of time is spent on these boards discussing how to deal with problems that have been around for a long time.
Some of my favorites among the "crunch" articles, besides those mentioned, include the "Tuatha De Danaan" article. Possibly, one section of the book could be devoted to real life cultures and mythologies adapted to the game. Also, the articles that Roger E. Moore (where is he these days) wrote about demihumans and their deities might be very useful for roleplaying purposes. (Currently, on thiese boards we have a poll on "Elves, Love 'em or hate'em. Perhaps we can have some insights into the different races and cultures in the game.)
"Giants in the Earth" might be good, adapted to 3.5. It might give players some ideas for books to pick up, or serve as a source for interesting NPCs -- or even as models for player characters to follow.
As for the Sheens, they could work well in a few settings. Realmspace is large, and the illithid are already an example of one type of invaders from distant worlds. The World of Greyhawk had S1: The Expedition to the Barrier Peaks. Eberron seems to be a cosmology that is cut off from other worlds, so possibly the Sheen in Eberron might have their origins in the ruins of Xen'drik -- a shadow of the past come back to haunt the present.
