Seconding Seanan McGuire's Midnight Blue Light Special, and really looking forward to
Tanith Low in the Maleficent Seven by Derek Landy.
Also, the Third Doctor short story in the Doctor Who 50th Anniversary Short Stories series (one e-story per Doctor) - neither the title nor the author have been announced yet, but I'm hoping it's someone good (first two Doctors' stories were by Eoin Colfer and Michael Scott, so they're definitely going for the current big names in children's / YA fiction as the series announcement promised).