The transformation to standard data types is not yet complete. Microsoft still seems to be fighting it with respect to Office. Yet, nobody today would seriously consider the camera in a cell phone useful unless it supports JPEG. MP3 and AAC are standardized and MP3 support is universal. MPEG-2 and MPEG4/AVC are extremely widely available, although not (yet) "free". We can debate how far this trend has progressed to date, but, at this point in time, there is no going back.
So, yes, "The PC" is dead as a data monopoly, but, it wouldn't surprise me to see Windows around for a long time.
Remember the biggest selling software on Macs is Microsoft Office for Mac.