After weeks of hints, Southwest announced its new fare last week. Any time a big airline makes such a portentous announcement, you need to take a look — and answer seven questions. 1. What’s New? The new Wanna Get Away Plus fare sits above the line’s lowest offering, Wanna Get Away, and below Anytime, its entry-level unrestricted fare. As the name indicates, it’s much closer to the low fare than the higher one. It remains capacity controlled — which means it’s almost never available within a week or two of departure — it’s nonrefundable and not changeable. As with all Southwest fares, however, it includes two free checked bags and retention for a year of the full dollar value of a ticket you change or cancel. The Plus part adds two potentially important and one trivial benefit to the base fare: • You can switch to an available seat on …