Maybe someone already mentioned this, but if not...
I am OK with paying for updates that offer increased functionality, provided security/bug fixes and maintenance updates remain free.
HOWEVER, I do NOT want to see Ads popping up in my OS apps as it sounds like they will be soon. While I love the user experience of Apple products, I am becoming increasing disturbed by Mr. Jobs business model of snookering you in on a paid product or service and then locking out the competition while force feeding unwanted advertising and leaving you only 2 options - opt in or stop using the product that you paid a premium for in the first place.
Maybe my understanding is off base, but that's where I'm at.