Black Library is taking pre-orders for a large series of upcoming eBook releases.
From their website:
This week we have a huge number of eBooks available! Not only can you pre-order April’s releases, you can also pre-order your short story of choice from Victories of the space Marines. You can also now get your digital copy of the Gaunt’s Ghosts novels Honour Guard, The Guns of Tanith and Straight Silver by Dan Abnett, as well as Titanicus.