Actually Sandy Bridge would be a pretty big spec bump, one that you wouldn't want to miss. As seen in the macbook pros, the sb mobile chips are now the speed of the current imacs. According to anandtech, the new desktop i7 chip with sb is about 30-50% faster than the current i7.
It was bigger thing for MBPs as 13" came from C2Ds and 15" and 17" used dual cores while they now use quad cores. It will still be a nice bump for iMacs as more models should go quad core but the CPU isn't the bottleneck nowadays so if you're looking for a web browsing machine, current gen is fine.
Looking at MBP's it's certain we can expect iMacs with SSD's. If not in base models, then definitely with custom builds. And as to them being thinner, well it's a speculation of course, but we've seen that with every update of Apple products.
What makes you think that we will see SSDs because of MBPs? MBPs DID NOT get SSDs. It's just like before, they are BTOs. BTO prices might have gone down a bit but that is normal and will likely happen for iMacs as well. If something, MBPs point that iMacs won't get SSDs as standard anytime soon.
It's much easier for Apple to use the same external design and case than make it 1mm thinner. iMacs are tightly packed machines already so I can't see where could Apple squeeze the extra space without sacrificing the performance. MBPs have been as thick since late 2008. Just because iPhones and iPads get thinner all the time, it doesn't mean that all products will with every update. When we will see a redesign, then maybe.
You didn't answer this one. What do you mean by major changes that might come to 2012 iMacs except for a redesign, if you don't think that Sandy bridge, Thunderbolt, SSD's and Lion are big enough?
To rephrase it, I think 2011 iMacs are the big change in the line, because 2012 might only have a design change and a slight spec bump compared to this years new iMacs.
I didn't say there will be major changes in 2012. There are new CPUs coming every year so with your logic, every update would be a major one. New CPUs and GPUs are just spec bumps, nothing more. If iMac got higher TDP CPUs and GPUs (maybe desktop GPUs), then I would say we are talking about a bigger update.
Thunderbolt is the only big thing unless iMacs get SSDs (I already explained why I don't see this happening). You can get Lion for any Core 2 Duo Mac so I don't see how you see it being a big deal. It most likely won't even be included in the new iMacs.
2012 will bring Ivy Bridge (probably 6-core CPUs) and AMD 7000-series graphics so I don't see it being much different from this years update. SSDs are getting more likely by that time. A redesign would make it a major update though.
With the 2011 MBP out my attention now goes to this year's iMac. Based on the Intel GPU used by Apple in the MBP I am thinking their high-end model will sport a $317 4-core 3.4GHz
Core i7-2600K (
"Sandy Bridge" (32 nm)) chip with built-in HD Graphics 3000 GPU. Would be nice to max it out at 32GB if Apple allowed for 8 SODIMM slots. This part shares the same 95w TDP as the BTO'd
Core i7-870.
Makes no sense to use i7-2600K. i7-2600 offers the same things (sans the better IGP) and it costs less. Unlocked CPU multiplier is useless as you cannot overclock the CPU in OS X anyway, and Apple does not care about OCIng at all.
Though there is the possibility that Apple could use a 6-core 3.46GHz
Core i7-990X (
"Gulftown" (32 nm))with no built-in GPU but it's $1000. It is limited to 24GB though.
This chip's TDP is 130w.
Too hot and expensive. That is Mac Pro stuff. i7-2600 is much better value too.