This current design is going to be a classic and stick around for many years. However there are some refinements Apple can make as time goes on.
- The MBP will slowly become more thin and light as Apple makes the board smaller and smaller.
- Speeds will slowly increase as Apple follows Intel's roadmap. RAM will likely stay at an 8gb max for some time, just like it did at 4gb.
- I think it is possible Apple will begin selling a range of colors similar to the nano-chromatic iPods. (unlikely, they seem to like to keep things more subdued in the MBP line. Too bad, I'd like this option)
- The optical drive is going to go soon. Either in this next revision or the one after. Its replacement will be downloads, software distributed on SD, the external superdrive and remote disk software.
- No new ports are coming. If Apple wanted to mess with HDMI, Esata et al they already would have. There are going to be fewer ports going forward, not more. The MBA is Apple's vision of the future, not some port studded monstrosity of a Dell. USB and FW will be updated to their replacements as time goes on. (USB3 and FW3200)
- No new buttons on the trackpad. No number of buttons could be as flexible as a large multitouch pad like they have now.
- GPU will continue to be a middle of the road part, Apple doesnt want to deal with the heat and expense of top of the line GPUs.
- Built in WWAN support either antennas and an empty miniPCI slot (unlikely due to space constraints) or a Gobi chip or somesuch built onto the board. I hope that they look beyond their partnership with AT&T (who's 3g network is garbage in the major cities) and make provisions for both CDMA, HSPA and (dreaming here) WIMAX.
In my perfect world, Apple would leverage the removal of the optical drive to make room for a user upgradable 2.5" bay. (Or 2 in a really perfect world) While also reducing weight and thickness now that the 'size inflexible' optical drive is gone. It would have the option of several colors (anodized, like the Nanos). Blue, red, black, green, pink etc. It would have a Gobi chip that could support wireless broadband on a good network. (Vzw/Sprint)
That is just about the only thing that would drive me to upgrade from my current 09 17". It is otherwise absolutely perfect.