"more transferrable" and "more portable" doesn't mean no extra work.
assets can be transferred so you aren't starting from scratch but that doesn't eliminate platform specific optimizations. it doesn't eliminate platform specific QA.
engine scalablity != game scalability.
@bold. Of course, but the QA is significantly reduced to consider testing for bugs caused specifically on that hardware.
In the meantime, dev time is reduced almost twofold, as the API handles the cross-platform deployment.
As for optimizations, this may help from the 2012 Q&A session of the same Corporate Strategy Meeting:
In this sense, what we should be discussing is not cloud gaming but whether dedicated gaming platforms will eventually die out and whether handheld gaming devices and home consoles will one day be unified. Naturally, our stance is that dedicated gaming platforms will not die out and we are determined to create a future where they will not. In terms of our platform integration, as I explained to you a short while ago, we are not saying that we are planning to integrate our platforms into one. What we are saying is that we would like to integrate software development methods, operating systems, and built-in software and software assets for each platform so that we can use them across different machines. This means that if we manage to integrate our platforms successfully, we may in fact be able to make more platforms. At the moment, we only have our current handheld devices and home consoles because if we tried to make more platforms, our development resources would be spread too thinly. The more we can share software across different platforms, the more development resources will be left for something else. Platform integration does not mean creating one type of platform, but the point is that the united method of software development will enable us to share our most precious software assets across different hardware. It is natural that there will be more things that battery-run devices can do thanks to technological advances and game consoles will become more powerful. However, if we try to linearly pursue this direction, software development will become so complicated that we will eventually face a situation where cost recovery becomes a serious issue. Therefore we feel that we are nearing a saturation point in terms of simply improving performance or enhancing graphics. What is far more important for the future of video games is whether we can make new propositions in other aspects and create games out of something that people never expected to see in the form of a game.
Of course they will program it for the best hardware and let the engine scale it down automatically, but they will not be focusing on getting all the juice out of the strongest system, that's already thrown out the window when considering a unified architecture.