I'm glad to hear of the news that Sanjeev Arora's team at Princeton was one of the winners for the NSF Expeditions grants, working on the general theme of complexity. I think it shows that some of the public relations work our community has been doing, especially with the NSF, is paying off in concrete ways. I also think that more money for theory generally just has to be a good thing -- it's $10 million more for theory than there was before.
That being said, I'll express two concerns:
1) It's odd to see so much money for theory concentrated into such a small geographic area. I realize that was the nature of the Expeditions program, and I don't fault the proposal for it. It just strikes me as strange when the general budget for CS theory is so small to earmark such a large sum of money to this project. It feels like an over-concentration of resources in what's already a small community.
The solution to this, of course, is to get more money for the general CS theory program. And I'm sure a significant chunk of the Expeditions money will go to open DIMACS-style collaborations like workshops and other events, minimizing this concern.
2) I know it's just the nature of theory, but reading over the blurbs about the various funded Expeditions proposals, I can't help but notice that while the others seem to have some sort of statement of clear goals to take things in new directions ("hope to create a new field of computational sustainability", "It aims to create an "open" alternative to mobile ubiquitous computing and communication that can spur innovations, which will have a dramatic impact on the choices users will have in the way their data and information is computed, stored and communicated", "The project aims to develop tools and theories for molecular programming--such as programming languages and compilers--that will enable systematic design and implementation of technological and biotechnological applications that require information processing and decision-making to be embedded within and carried out by chemical processes."), the complexity grant will "hope to better understand the boundary between the tractable and the intractable" and "attack some of the deepest and hardest problems in computer science". Doesn't that sound, I don't know, just like business as usual? My concern is that it's probably important to the theory community long-term for this Expedition to have some major concrete success attributed to it at the end of the day. I have no doubt that good things will come out of this, just based on the people, who already do good work -- but will the output be the sort of things that in retrospect justify this investment?