the most exciting releases the past year and a bit have been (for me) : Knights, the end times and now this. Much more interesting and exciting than the endless codex update cycles which I had been bored of for years. Not completely new but still fresh enough - A lot of people wanted harlequins as an army (along with the usual suggestions of admech, traitor guard, genestealer cults, exodites blah blah) so actually seeing one of these actually happen is a bit of a big deal and pretty awesome IMO.

Makes me wonder what they might do next as well. Could we possibly see genestealer cults, mechanicum or even a whole new alien race? It doesn't seem as unlikely as it used to in the past...