By 2014 the Mac Mini won't be slimmer.. it won't even exist.
All computing will be done in The Cloud. We won't need computers on our desks any more because all the software and data will be floating in the clouds. Input devices such as keyboards and mice won't be necessary because we will communicate telepathically with The Cloud. The final transition began at midnight on December 21... That is the true meaning of the Mayan calendar event yesterday.
Apple has known this for a number of years and has been slowly evolving toward the inevitable transition. The primary goal is to gradually do away with all the computing devices that people have come to depend upon in their everyday lives. Unlike most other PC companies, Apple is very concerned that its customers not be too freaked out when the ultimate destination is reached. (It is no accident that Apple is located in central California, a place that is well-known for being open to New Age ideas. Microsoft has always been way behind Apple in this regard in part because it is located in Seattle, which is far away from any energy vortexes.)
The first step was to remove floppy drives from Macs. Optical drives were next; that process is almost complete. SSDs were created so people would become accustomed to using a data storage device without moving parts.
Apple introduced Macs that gradually became lighter and thinner so that consumers wouldn't notice that the hardware was really disappearing, slowly but surely...
Bluetooth devices freed us from cables that will no longer be necessary because The Cloud doesn't have any ports. Apple's Thunderbolt technology is the final step: it is extremely fast and the name was carefully chosen so that computer users wouldn't be frightened when the release of OS 10.10 (Sky Cheetah) turns all of our Macs into organic pumpkins. (I have a great recipe for pumpkin pie if anyone is interested...)
So try to enjoy the waning of computer hardware. Soon the days of speculating about the release of the next Mac, arguing about the importance of a discrete vs. integrated GPU and posting videos of box-openings will only be a distant memory, experiences we can share with our grandchildren when they ask us for stories about how life was before The Cloud.