I have a late-2012 iMac specced without the fusion drive ($250 for 128GB was stupid). It's my understanding the stick drive found in MBP can be used for the fusion drive. OWC sells this kit: http://eshop.macsales.com/shop/SSD/OWC/Air-Retina/Apple-MacBook-Pro-Retina-2012-Drive-Internal-Flash Will this work in my iMac as a fusion drive DIY? $299 for 480GB is almost reasonable. I'm fairly confident OS X's fusion drive technology can scale up to larger drives. This may be an alternative to waiting for 1TB SSDs become reasonably priced.