OS X was a marketing name and was dead for a while now.
Besides the CPU arch change and a slightly refined UI it is pretty much the same.
Besides the CPU arch change and a slightly refined UI it is pretty much the same.
It'll be interesting to see what things look like later since this architecture transition will weed out some problems Apple see, but in a different way. On the other side of the transition they can make further changes to lock down the OS with fewer issues. This has to be Apple's ultimate goal because it's what serves their needs best from many perspectives. I wouldn't suggest it serves the needs of many devs though.