Roomorama is not the only one in the person to person travel accomodations game. The company is in a space that’s been well established by other players: CouchSurfing, Vacation Rentals By Owner and, of course, AirBnB. While there's an AirBNB API planned, the only room rental site that is currently public with its platform is the the Roomorama API.
The Roomorama API currently allows for everything you could want from their service except access to reviews and ratings. It’s possible to list the destination cities and property listings in those cities. Each property has a long list of attributes that could be used to filter and select the accommodations that are most fitting to the traveler’s needs. Properties can be added and updated through the API as well.
One thing the Roomorama API does not do, which may make it a little less interesting to developers, is book a stay. The feature is missing because with Roomorama you don’t book, you inquire. It seems that the reservation system is a bit more “high-touch” and less automatic, which is understandable since you are dealing with an individual and not a full on corporate hospitality company. Still, when AirBNB launches its API, AirBNB will pay developers for referring bookings. If bookings can't happen through the Roomorama API, it will be hard to convince developers to choose Roomorama when they can make money with AirBNB.
All the technical pieces are there: it's RESTful and gives you either JSON or XML. Here's to hoping the company is able to expand its API offering to include a way to pay developers. I'm tempted to be the first in the state of Maine, USA to list a property on Roomorama.