Where is the best place for would-be FR authors to submit their short stories with a view to publication? Dragon aren't accepting fiction and I couldn't find anything on WotC.
There is a rumour going around that I have found god. I think is unlikely because I have enough difficulty finding my keys, and there is empirical evidence that they exist. Terry Pratchett
While many of us would love to write in the Realms, it's a sad fact that Wizards does not "accept unsolicited submissions for our shared-world fiction lines: Forgotten Realms, Dragonlance, Eberron, and Magic: The Gathering." That's a direct quote from their Book Publishing Writer Resources page. However, that page does mention they'll accept submissions for their "speculative fiction imprint", and has a link to the guidelines for such submissions. They also have a FAQ and a list of recommended books for writers.