The past few years have seen a resurgence of ancient mythologies, especially Greek mythology, in children's books. Most of this can almost certainly be credited to the popularity of the Percy Jackson series. In many ways Percy has done for mythology the same thing Harry Potter did for magic -- create a huge interest in books in this area. Granted, there were books with Greek and Roman mythological characters before Percy, but there are a whole lot more of them now.
And now, the desire for mythological books is spreading into other pantheons as well. Last year the Norse were represented in the book Runemarks and Pinkwater has a couple of books (The Neddiad and the Yggyssey) based on North American indigenous religions. But it looks like the next big round of mythological books will be Egyptian based.
Just like zombie is the new vampire over in the teen section, Ra is the new Zeus over in the midgrades. According to gossip I've been hearing all sorts of publishers are looking for Eyptian-themed books for all sorts of age ranges. There is definitely an opportunity out there for those of you who happen to have an Egyptian mythology manuscript lying around.
I am (coincidentally -- I do not pretend that I forecasted this trend several years back -- I'm good but not that good) participating in this trend by putting out my own Egyptian-based book in October. Although the book is more of a historical fantasy rather than a mythological fantasy, the god Amon-Ra does make an appearance.
And all this talk about mythologies leads me to my writing prompt for this week: Google an unfamiliar mythology. Using some aspect of the mythology that interests you (character, place, idea, etc.), write something. Go to http://buriedintheslushpile.ning.com/forum/topics/mythological-fiction to post what the prompt inspires.