Everything you said seems to be right on cue. I'm not entirely sure if portrait / landscape would do much good... because we have it as landscape now, it just seems like the best way of doing it. And maybe it is just me, but how often do you find working on computers to have your browser in a portrait-like setup? Most of the time it is in a landscape-form. Now sure, give us the choice, but I'm betting most people will stick with landscape pretty much all the time.
Landscape only is not a problem. In fact, if I had to choose only one view, that's what I would choose. Like you said...choice would be nice, but the main deal for me is all the extra real estate. Sometimes "less is more".