According to the post, all Romulan Warbirds will come with a cloaking device, subterfuge racial trait that makes detection difficult and warp cores that add singularity abilities. The game will also feature several smaller Romulan crafts, such as the Tiercel Shuttle, Kestrel Runabout and Scorpion Fighter, and several kinds of warships.
The post also contains a progression chart for ship tiers, which details how higher quality ships can be obtained. You can read the full update here.
Legacy of Romulus is currently slated for launch May 21. Previously, the publisher detailed the expansion's Starter and Legacy Packs, which include additional content.