I think the first question to ask, before talking about how we can move these two packages closer together (I assume the end goal would be to merge them), is whether it is desirable to do so.
The issue really has nothing to do with photobook or complex survey themselves. I think a case could be made for combining them, and a case could be made for keeping them as they are. As I see it the question is more general. Both photobook and Malte's work with complex survey were done on spec for clients, and I believe that when a client pays for a package to be built, they should have a reasonable expectation that the package will remain one that meets their needs after they contribute it. That is, others will hopefully contribute bug fixes and small enhancements, but not make large structural changes.
I am not saying that Sloan and Malte's client would not be happy with a combined package - we don't know how it would turn out. But the potential exists for the needs of the community to clash with the needs of a funder, and then what are their options? They can refuse to allow their package (of which they are the maintainers) to be modified, possibly creating hard feelings and/or forcing yet another package to be created, or they can use the modified package even though they don't like it, or they can stick with their version and lose the benefit of the community's bugfixing efforts. The first is probably the most palatable option to many funders who find themselves in this situation, but not necessarily the best for the community. Of course, yet another option is for them to not contribute their work at all, and I'm afraid that we may encourage them to make this choice if we don't do something to protect the rights of funders, even though that's not the pure Open Source way.
I don't know what the answer is, but I believe this is an issue that will come up eventually, as more and more work is done on spec and then contributed. I believe it's one we should discuss and come up with guidelines for, so that funders know what their rights and risks are in this development model.
