As with many of the Macintosh products, expect to see possibly a thinner Macbook Pro, an even thinner Macbook Air (perhaps maybe a 15 inch model). The iMac looks good where it's at right now, maybe a boost in performance will certainly attract more consumers.
The design of the current Mac mini is fairly new, but by 2012 hopefully all the models will have a quad core processor, and Apple should do away with the integrated graphics, much like how in 2005 the Mac mini had started off with a discrete graphics chip.
If theres one part of the tech market where Apple have not competed in, it would have to be the television industry. Rumor has it that an Apple TV (not the set top box) might be set to launch in 2012, its a pretty big move for Apple, but certainly it will provide a good amount of support to the mediocre sales of the Apple TV which is currently at $99.
2012 will be hopefully another big year for Apple and it might be a different one too, hopefully Tim Cook will be able to lead Apple if not the same way Jobs did, but at least towards more success.
MacMiniTech will also continue to post throughout 2012, so be on the lookout for future posts!
Tim Cook will look to lead Apple throughout 2012.