In the literary Star Trek Universe, the Borg invaded the Federation and their allies space in large numbers and destroyed many planets, literally bringing the Alpha and Beta quadrants to their knees. This was in the Destiny trilogy series in 2008 (my review here). This happened 6 years before the destruction of Romulus which lead to the events of the recent Star Trek movie and the bifurcation of the Star Trek universe into the original and the new version by J.J.Abrams.
In the literary Star Trek universe with the Federation weakened by the Borg invasion, a new group of interstellar civilizations formed the Typhon Pact to fill in the power vacuum. They are the Romulan Star Empire, the Breen Confederacy, the Tzentkethi Coalition, the Gorn Hegemony, the Tholian Assembly and the Holy Order of the Kinshaya. This is a bold move to steer Star Trek into a new direction with new enemies and allies. I look forward to reading about the Typhon Pact, of which only one novel has been published Zero Sum Game.
I like the introduction of a new class of starship, the Vestaclass which uses slip-stream technology which was first mentioned in the Star Trek Voyager series. I appreciate the sleek design of the USS Adventine NCC-82602, captained by Ezri Dax.
source: Star Trek magazine Oct/Nov 2010