There are many interesting ideas about the cosmological constant problem; none rises to the level of "promising".

• There are many interesting ideas about the cosmological constant problem; none rises to the level of "promising".

• An ordinary cosmological constant is a perfect fit to the dark-energy data, even if we can't explain it.

• Dynamical mechanisms are interesting and testable; to date, they raise at least as many problems as they solve.

• My suspicion: we just got lucky. Our task then is to figure out how to correctly calculate the vacuum energy. This will require a significant breakthrough.