Here's a quick bit of Mystara-related news. Bruce Heard started a blog recently. Bruce was the product manager at TSR through the period of creation for the Gazetteers of the Known World, the Almanacs, Hollow World, Wrath of the Immortals - the heyday of Mystara. One of the more interesting series at the time was The Voyage of the Princess Ark in Dragon magazine; each installment covered the voyage of an Alphatian sky ship to previously undiscovered areas of Mystara, and then included maps and game stats for using the areas to expand your campaign.
I've often said here on the blog that while it seemed TSR was focusing corporate oversight on AD&D 2E, the classic D&D line was given freedom to move in other directions, and that creativity can really be seen in these Gazetteers and products of late 80's / early 90's D&D. You can get some background on the creation of the Glantri Gazetteer at Bruce's place: Bruce Heard Q&A
If you're not sure what is the fuss about all of these Known World Gazetteers, a good place to start is over at the Age of Ravens blog; Lowell Francis has been putting up excellent reviews of the gazetteers in order: Age of Ravens Gazetteer Reviews
I haven't done any Mystaran reviews per se, more like paeans and odes to Mystaran goodness. You can see my own exaltation of Mystara's gonzo excellence in some of these posts: