I'm thinking of upgrading to the new 15" MBP. My only concern at present is the NVIDIA GeForce GT 750M, which supports external displays up to 2560*1600. With a (presumed) 4K Thunderbolt display not too far away, and 4K becoming the norm in the near future, is it 1. Possible to user-replace the graphics card with say the GT 760M (which does support 4K) or 2. Likely that we will be able to say choose the 760M when configuring the MBP in the near future?
I'm not too familiar with MBP lifecycles and how often things like the graphics card is updated.