The new imac should definitely have some sort of re-design externally, my personal opinion of the current looks of the imac is a good one, having one huge black screen isn't something that will be overly visually appealing so I'd say apple with stick with something very similar to the current 'chin' design, unless of course they went for another main colour, which is also unlikely in my opinion.
Specs wise I'd like very much to see an improved display, I have heard rumours that instead of going full retina with the imac they will simply up the ppi to 170-180 ppi which would give a fantastic screen as well as being much more reasonable and likely due to current graphics performance, although current apps aren't yet suited to this which does present the question of will they bother with this at all as current apps designed for 120-130 ppi?
I think graphics card wise its also fairly obvious what will happen, as it has already been talked about and confirmed several times.
Ivy bridge is another thing that is certain for the new imac, however with graphics improvements of up to 70% with Intels new ivy bridge CPU's some of the base models may even stick to that instead of using a dedicated GPU, this could be one way of apple saving us from spending more on the new imacs what with so much improvements going on elsewhere, however I still want a 2gb graphics card for editing and I highly doubt the built in GPU can give me the same performance as that.
I'd say its also certain for USB 3.0 to be included however I wish companies began embracing Thunderbolt as its already got 2x the bandwidth of USB 3.0.
Having a HDD and an SSD is essential for the new imac but I'd be surprised if they included an SSD as standard as the market they are aiming at will almost certainly need atleast 1tb of space to house movies, images and files, not to mention the increased cost of this, although SSD are cheaper now it will still add cost.
As standard it could be possible for apple to maybe include a 32gb smart-cache SSD as seen on the newer top end Dell XPS computers, with a 1tb hard disk, this would of course be the base model imac and from that you could upgrade the SSD to something larger (256gb) and upgrade the HDD to 2tb. SSD are the way forward and I'm very interested to see what Apple do with this dilemma.
Outside of the computer I definately would love a backlit keyboard however it would require power and Im not a fan of having a cable, plus Im not sure Apple have any need to change from the current keyboards on offer, as an after thought it would be nice if apple added a 3.5mm headphone port onto the keyboard to make plugging headphones in much easier and less in the way. There may be a re-design of the mouse but I also think that it isn't really the focus of the new re-design for 2012 imacs.
Software wise I am apprehensive about saying Mountain Lion will definitely appear as many rumours have said it still needs a lot of work so as previously mentionned in the stream a complementary upgrade for 2012 imac customers would be a lovely gesture from Apple.
Apple are quiet conservative about upgrades and major re-designs so Im unsure of what exactly they will do with the imacs, I do hope its a feature in WWDC but they could release it tomorrow and I'd still be happy.
