What we know for sure: There'll be a free gift ship for both factions. It'll be rewarded from a mission with voice acting from Tasha Yar's actress somehow involving the Battle of Narendra III (where the Enterprise C was destroyed).
What we're pretty much sure about: The rewards are the Ambassador and Kamarag class ships shown off in recent Friday screenshots.
Everything else is speculation. A sideways dev comment in the last Ask Cryptic sounds like these ships come in tier 3 and tier 5 versions. We don't know what tier the free version is. It's assumed it'll be bare bones and a better paid version will follow (like the 2nd anniversary ships).
We don't know the stats. In fact, we're not completely sure what kind of ships they'll be yet. They certainly look like cruisers in basic design, but the recent trend in oddball ships have invalidated a lot of basic assumptions about things like that.