OWC has disassembled the new 27" iMac
Well, we have good news and bad news for you.27" Mid 2010 iMac Disassembled
The good news is that the SSD bay available in the new iMacs holds a standard 2.5″ form factor drive, which means you can install a high-performance OWC Mercury Extreme SSD for the speed advantage over Apple’s SSDs.
The bad news is that, unless your Mid 2010 iMac originally came with an Apple SSD, there’s no graceful way to install an OWC one. The appropriate mounting bracket and connector cables are nowhere to be found on the non-SSD models.