The site seems to be promising to later evaluate a rather large number of widely ranging predictions. If it manages to actually keep this commitment, it will make an important contribution. The five year limit on prediction horizons is unfortunate, but of course site authors have every right to limit their effort commitment. I do suggest that they post the date that each prediction was submitted, along with the date it was made, to help observers correct for selection effects.
Wrong Tomorrow by Maciej Cegłowski is a very simple site for listing pundit predictions and tracking them [FAQ]. It doesn't come with prices and active betting... but a simple registry of this kind can scale much faster than a market, and right now we're in a situation where no one is bothering to track pundit predictions or report on pundit track records. Predictions are produced as simple entertainment or as simple political theater, without the slightest fear of accountability.
This site is missing some features, but it looks to me like a starting attempt at what's needed - a Wikipedia-like, user-contributed, low-barrier-to-entry database of all pundit predictions, past and present.