Sitcoms are generally multi-camera comedies, though there are many exceptions. It is basically a much quicker and cheaper way of filming a program. Single camera set ups are used for dramatic television, movies and location shooting generally, while live events, news and shows in front of an audience are better served with multi-camera set ups. Again, there are tons of exceptions.
The advantage of single camera shooting is you can set up and perfectly light a scene from every angle, and let each actor deliver their lines cleanly. The huge disadvantage is with time, as actors generally deliver their lines once on camera, then lighting, sound, crew etc. have to move to reset the scene while the actors work again with their backs to the camera while their scene partners have their onscreen moments. It can often lead to small continuity problems, with actors arms out of position or drink levels changing from shot to shot. Still, it often produces the best performances as actors can redo lines until they are just right, which is why it is the favored form for dramatic film.
Multi-camera comedy lets performers work off each others energy, and has much more ad-libbing involved. It is also better suited to shows like Cheers, where most of the action occurs on one set. This is usually the deciding factor for an audience as well, if there is only 1-2 sets then they can film everything on one stage, otherwise there is too much moving around. The biggest factor is time, as shooting a scene with a different camera on everyone in the scene means they only have to do it once error free then move on to the next scene.
Based on the description of Hitched we've heard so far, I would expect it to be primarily set in the newlyweds home. It might be entirely set there, making it a logical choice for filming live, but who knows. People might not like laugh track much, but Hitched is on CBS, home of Two and a Half Men and The Big Bang Theory, both of them are hugely successful sitcoms with laugh tracks. I am sure the pilot will be using a laugh track, though if it gets picked up we can all hope it gets the live studio audience treatment as many actors really seem to feed off audience reactions. It would be nice if Kristin's fans could show her some love and support live like that.
One oddity in the laugh track vs. live audience format is How I Met Your Mother. It is completely filmed and edited, then the episode is shown to an audience with their laughter taped for the broadcast show.