Interesting article in Science on the challenge facing Dr Stern in taking over NASA's Science Mission Directorate
Bottom line is that he is stuck with a zero-sum game and that except for some innovative cost cutting it is a game of trade-offs. Something will be cut.
An accompanying article on science and the Moon is even more brutal - there is none.
The focus is on exploration, not science, and the Lunar program will not contribute to science done on the Moon or based on the Moon - which is a pretty nasty surprise for the lunar science community who were rather happy about the return to the Moon.
Somewhere in planning the exploration no budget was set aside for actually doing any science, again begging the question of what is going to be done. As the exploration budget gets squeezed by the inevitable cost overruns, what science there was planned is being cut. No robot rovers, no orbiters, no sample returns, no lunar observatories.
Of course this will change, yet again, sometime, and the article notes that the tech developed will have trickle down benefits to science missions in the long run, much as the Shuttle did, for all its flaws.
In a nutshell, this is Manned Spaceflight 3.0.
1.0 was Mercury, Gemini, and Apollo, with Skylab as an excuse to extend the mission.
2.0 was STS, with the ISS as an excuse to extend the mission.
Manned spaceflight is hugely dangerous and expensive, and extremely profitable. The same players who raked vast fortunes from the 'space race' (remember the USSR?) needed to make more of same when 1.0 petered out, and hence 2.0 -- the STS. Now that the STS is geriatric, they want to make more and more of the same with 3.0. All the available money will get spent and we will have nothing to show for it.