According to the various Mac Blogs and Rumors, the 15" Macbook Pro Retina is going 16GB as standard. I don't think I'll be uprading unless there is an option for 32GB RAM. Since I already have 16GB of RAM, I don't see a compelling reason to upgrade. I notice the NVIDIA GPU is now 2GB which will be handy.
I don't think it is a worthwhile upgrade to my 2.7GHZ, 16GB RAM, 760GB SSD build. It is still the best laptop I've owned and is still plenty fast.
However, I'm yearning for 32GB RAM which I have on all my workstation desktops.
16GB is bare-bone minimum when you run a lot of VMs. I can definitely feel the need for more RAM. 2GB of video RAM would be good at driving two 27" monitors. I can definitely feel some lag right now.
Storage wise I'm still good. I've only used 300GB of my 760GB. It is good to have 40 terabytes accessible via Thunderbolt so I've kept local storage to mostly scratch work.
I've thought about going back to Lenovo but I want stick to a Thinkpad over their consumer Yogas. A Thinkpad W540 is out of the question due to the mammoth size. And Linux's HiDPI isn't still as good as OSX. So for now, I'm going to stick to 15" Macbook Pro Retina.