I think 2012 will be a transition year, in management as well as in products, to continue transforming Apple from a computer company (the old Apple Computer Inc), to a mass-product company.
Ivy Bridge
A new generation of Mac will come with Ivy Bridge, that will mainly improve over Sandy Bridge, except for one point: HD4000 GPU!
The Ivy Bridge is the last evolution from the core micro architecture that appeared on the Core™2 CPU in 2006 (yes 5 years!), and in mono-threaded application, there are few progress, the most obvious is the Turbo-boost that speed-up the core up to 4Ghz depending on the CPU.
Sandy Bridge came with HD3000 & HD2000 GPU integrated to the CPU, that offered a performance-level similar to nVidia 320M with 2-monitor support. Ivy Bridge’s HD4000 will support easily 3 monitors with 4096×4096 resolution, and 2X performance increase: discrete GPU are less and less necessary!
Thunderbolt on PC
Thunderbolt on Mac as been a failure this year with only 2 peripherals available, 10 months after the launch!
Intel will launch at least 1 high-end motherboard for PC computers in 2012, but except if an OEM or big player (Dell or HP) have a full range of PC with Thunderbolt, it’s unlikely that this technology will emerge.
If it don’t get traction, peripherals will be sparse and too expensive, and if Thunderbolt succeed on PC, we may see many Thunderbolt peripherals without Mac OS X driver or support (exactly as ExpressCard or PCI-Express card for the same exact reasons!).
MacBook Pro & MacBook Air
Now that the MacBook Pro is as closed as possible, making hard to replace hard-drive or memory, having many incompatibilities with actual SATA 6Gbps SSD (cable is the culprit!), no more ExpressCard/34 port, you have to expand it using Thunderbolt peripherals if they finally go to market and if you can afford to pay 2X to 3X the price of USB3 peripherals!
Apple will probably discontinue MacBook Pro 13″, useless at this time with a 13″ MacBook Air that is lightweight, nearly as performing, less expensive and have a better screen! ouch!
MacBook Pro 17″ will probably loose it’s ExpressCard/34 port, that enable full use of USB3 or eSATA, 3 years after the MacBook Pro 15″
MacBook Air, lightweight powerful computer without discrete GPU will be the flagship of Apple, with a 15″ MacBook Air using Ivy Bridge and HD4000, that will perform as well as the Radeon 6490M of the last year MacBook Pro 15″, offering 1680×1050 resolution and GPU OpenCL support. Probably the most attractive MacBook Air for “Pros”
Mac Pro : sic transit gloria multi
Intel is not producing chipset with Thunderbolt, and don’t plan to. They don’t offer Thunderbolt PCI-Express expansion card, and announced they never will as Thunderbolt presentation. They don’t build motherboards with Thunderbolt, but plan to offer one motherboard on Q3’12 or Q4’12 with Thunderbolt.
Mac Pro have not been refreshed since 2 years, even 21.5″ iMac may be faster for some general tasks, and Apple is changing it’s “Pro” line of software to pro-sumer line (Final Cut Pro to Final Cut Pro X is the best example), also disregarding IT professional while discontinuing XServe line, replaced by Mac Mini Server or Mac Pro Server (lol).
It’s clear that the Mac Pro as we know it will disappear from the Mac line in 2012 or 2013 at best! 
USB 3
Intel will natively support at least 4 USB3 port at full speed on it’s Ivy Bridge chipsets, and it’s pretty sure Apple will implement USB3 on 2012 Mac computers.
But as USB 2 implementation was often flawed, using USB 2 HUB inside our Mac even when the Intel chipset natively offered enough port to have them independent, USB 3 support will be very limited, and I expect to have only 1 USB 3 port on our 2012 Mac, probably using a PCI-Express 2.0 1x USB3 chip to cap the bandwidth at half the USB 3 speed! You bet?
Closing platform
From the Mac App Store rules, the USB 2 shared port, Thunderbolt-only policy of expansion, discontinuation of Pro lines, Lion over-simplification of the interface, Apple is trying to make their computer more mass-consumer friendly while abandoning the Pro from their root: a kind of “iPad-ification” of the computer line…
We hope there will be many hackers and incredible developers that will continue to offer us the best for our Mac, even if we have to install them the old-way (no Mac App Store for them!), or even at some point jailbreak our Mac to expand it!
Happy new year 2012 to all!