Probably won't mean much to macs, iphones, etc. Microsoft has usually been pretty good about support on non windows platforms. In fact, I've heard that they tend to update Office more frequently for MacOS than Windows! In any case, it doesn't matter much for iPhone users, we've got facetime (or they do... since I don't have a 4 yet). Android probably has a similar system, and it probably won't be long before the two HAVE to become compatible.