upon reading that it seems that this "always on, always connected" only means, that it has a standby mode in which it can still update and maintain network connection (didn't the 360 already do the same?) and not that you need to have your console connected at all times to use it
the part that says it won't play games from disc but rather install all of them and may start playing while installing is curious though - that pretty much rules out below 500GB HDDs and indicates there might be several skus with different HDD size