Sealing another component in, Apple's latest Mac shenanigans include changing the type of cable that attaches to a hard drive. The end result is a hard drive that can't be user upgraded or replaced. Get ready to hand Apple a load of dollars to change a borked hard drive.
It's becoming a little ridiculous what Apple is doing. First the iPod included a non-replaceable battery, then the iPhone, then the MacBooks received a sealed in battery design, then MacBook Air's had their RAM soldered in and now Apple's killed user-serviceable hard drives in their iMac line. See where things are headed?
According to MacSales, the new iMacs use a 7-pin power cable instead of the standard 4-pin cable to connect to new hard drives. The cable change is said to regulate the temperature inside of the iMacs with Apple's firmware to ensure the computer doesn't overheat and explode into a million pieces of glass and aluminum.
The short conclusion is, if you want to upgrade the hard drive or it fails, you'll have to hand your iMac over to Apple to replace and it's going to cost a lot more than servicing it yourself. Apple generally tends to overcharge for its hard drive upgrades and replacements. Now customers have no choice but to pay up.
It couldn't be more clear-cut that Apple does not want you tampering with their hardware guts. For most Apple customers, this might be fine, but as a person who's replaced a hard drive on every single Mac I've ever owned, whether that was due to to failure or an upgrade, I can say losing the ability to replace the stock drive is a big downer.