"Actually, no. Tim Cook said that Apple would have "something great for our Pro users later in 2013.""
You're 100% correct. Too many people automatically assume it'll be a new Mac Pro. If you check out the link below, Sharp has shown a 31.5" 4K display. Just to speculate maybe Apple will release an iMac Pro with this 4K display and have that as their answer for the pro market. Who knows.
http://www.avsforum.com/t/1428193/4k-i-have-seen-the-light/60
I sure hope not!