The next Discworld scheduled is another Tiffany Aching - from Amazon.co.uk:

'Tiffany Aching is a trainee witch - now working for the seriously scary Miss Treason. But when Tiffany witnesses the Dark Dance - the crossover from summer to winter - she does what none has ever done before and leaps into the dance, into the oldest story there ever is, and draws the attention of the wintersmith himself...As Tiffany-shaped snowflakes hammer down on the land, can Tiffany deal with the consequences of her actions? Even with the help of Granny Weatherwax and the Nac Mac Feegle - the fightin', thievin' pictsies who are prepared to lay down their lives for their 'big wee hag' ... '

while I enjoy the Nac Mac Feegle and always happy to encounter Granny again, I'm still trying to decide what to make of these Discworld novels intended for a younger audience.