EOS will be an abstraction of two already proven application specific blockchains. A lot of the work has already been done, so completion of the project is likely. The plan is clearly laid out and seems achievable.
Watch some of the more technical presentations of the project and interviews with team members. They are very well versed in the tech they are developing, potential issues that can arise and how they plan to deal with them, etc. The level of detail in their answers would not be expected from representatives of your average ponzi scheme.
Dan should at this point have a lot invested with respect to his personal brand in this project.
Abandoning a project for which a lot of work has already been done, that one has invested a lot of time into planning and defending the technical details of in public, and disappearing with the money, especially if you are a rather public figure (as pointed out in the video), would be incredibly stupid. Not to mention that pretty much the entire team are already multi-millionaires. In this situation, they have more to lose than to gain by doing so.