If they do keep adding mics to the "miclibrary" and have accurate info of the frequency responses it seems like that alone would be a pretty neat resource to have on hand immediately. You can presumably (or should be able to at least) look up all the polar plots and response graphs for mics from the manufacturer's websites, but having a large library of mic information just in an app seems pretty cool to me. (as in the right hand picture at the top of the page linked) Even better if they added in some sort of comparison feature to look at two, or more, separate response graphs at once.
The visual representation is possibly a little 'gimmicky' as one should probably already have an idea of the polar pattern he or she is using, but still looks pretty nifty....well, If it works....which I would imagine is not as pretty as the demonstration.