I was looking at David Mack, and Keith R.A. DeCandido books on my Nook earlier today, and I saw that they had the Cross Cult German versions of the Destiny trilogy and Demons of Air and Darkness available for the Nook now. I didn't look at any others so I don't know if there's more than those four available.
They've started to do eBooks in April, and are basically busy digitalizing their backlog at the moment, I think so far only the Enterprise novels get simultaneous releases with the print books if I'm not mistaken 2011 eBook releases (not quite up-to-date I think, as both the July and August books are already available I think) They're also available at the various amazon outlets BTW.