Keep in mind that Apple only makes a redesign once every 4 years. The PowerBook G3 was released in 1997, the PowerBook G4 in 2001, the MacBook Pro in 2004 and the unibody MacBook Pro in 2008. Apple never considerably changed the internals within a design generation, offering only incremental updates to the CPU, GPU and storage capacity but keeping the same screen and storage type.



I think the next MacBook Pro will be no exception, and I expect it to last from 2012 to 2016 without needing to update its screen or storage type. While some people aren't ready yet for the loss of the optical drive, and even more people aren't ready to sacrifice the large capacity of hard drives to get an all-SSD laptop, I think it's inevitable at this point.



While SSDs are a bit expensive for their capacity right now, you have to consider how much smaller they are compared to a HDD, whether in 1.8" form or blade type like in the MBA. While I'm sure some people would like a HDD+SSD combo right now because of the high price of SSD, I think this will soon be a non-issue and HDDs will definitely be a thing of the past later in the design cycle, which I remind you should end around 2016. Saving the space of a 2.5" HDD inside a laptop is enormous, and I'm sure people will care more about battery life than about having an outdated secondary HDD, especially in 2015-2016.



I'm sure SSD prices will be much lower in the next MBP than in the current one. For one, they will be mass producing them. Mass production of millions of units of anything allow much lower prices. Just look at the new Retina display in the iPad, this thing would have cost way too much to be put in a 500$ tablet if it wasn't produced in millions. Also, Apple recently bought Israel-based flash memory part maker Anobit, so it should be cheaper if they produce those themselves. Apple also generally tend to have a smaller profit margin for their laptops at the beginning of a design cycle than at their end, just for the sake of offering design and price uniformity throughout years.



I expect the SSD options to be 128GB, 256GB and 512GB to start, with maybe a 1TB SSD option later or as an expensive BTO option. While this would represent less storage than current MBPs, you have to consider that Apple thinks long-term. They know SSD is the future and that they won't redesign the MBP for another 4 years. Just look at the first iPhone and iPod touch. The iPhone only had 4/8GB of storage and the iPod had 8/16GB. That wasn't a lot of storage, but they still did it because they knew flash storage-based mobile devices were the future, and Apple wants to show iconic designs that last throughout the years. They constantly want to prove they can predict the future and that they were "right from the beginning" in order to make themselves look like the tech leaders.



Since the design will last for another 4 years, I also expect the screens to be excellent. If they market them as Retina displays or not is only up to Apple, as they can pretty much play with that term by just choosing any "typical viewing distance" they want. You can already say the current 17" MBP has a Retina display if you sit far enough from it. I think the real question is whether or not Apple will attempt to double the resolution on each axis, as they did with the iPhone 4 and the new iPad. While those screens would be definitely pricy to make, they would solve the problem of having tiny UI elements on high-res screens. Just imagine using OS X's UI on a 1920x1200 13" screen, everything would be sharp but way too small. Doubling them at that resolution would however make them too big, like on a 960x600 monitor. To have screens that appear sharp to both our 2012 standards and the 2016 standards and that have reasonably-sized UI elements, I think Apple has to aim high with 2560x1600 and 2880x1800 screens.



As for the guts, the MBP will keep packing the same Intel high-end mobile LV CPUs and discrete graphics, at least in the 15" and 17" models, which could possibly be the only new MBP models anyway. The exact specs will depend more on Intel/Nvidia/AMD than on Apple. The lack of HDD and ODD will free up some space, but there's not much Apple can do to improve performance if they already pack in the best processors Intel has to offer. It's not like they will decide to have a special motherboard with dual CPU or anything crazy of that sort. That means that even with decent cooling and upgraded performance, the new MBP will still have room left to either pack in a larger battery or shrink the case size to allow for a thinner, more portable machine, or realistically a mix of both.



tl;dr: Don't forget the new design will last until 2016, so they have to pack in future-proof parts like SSD and a high-res screen. Hard drives will be obsolete long before the end of this design generation so don't expect a HDD+SSD combo since portability and longer battery life will be more important than carrying an obsolete piece of tech in the coming years. Apple will do everything they can to offer SSD at a reasonable price so they can move forward to a new, future-proof design. The screen could be double the resolution of the current ones or not. It will be more powerful yet probably offer both better battery life and thinner design. Nothing is mutually exclusive here with all the space we save with the removal of HDD and ODD.



tl;dr;tl;dr: The next MacBook Pro is gonna be awesome.