Your faction is the Federation in Star Trek Online, but in your heart you long to be like the sneaky, underhanded, and intriguing Romulans. Alas, you can never really be the same… but you can command a Romulan ship in the very near future. Yes, the studio has revealed that players will soon be able to pilot all but a very small number of Romulan ships regardless of whether or not your captain belongs to the Federation, the Klingon Empire, or the Dominion.as you can see from the announcement, that still leaves a lot of ships available for any captains to fly freely.
Source: Official Site. Cheers, CapnLan!