I like the idea of interactive added to digital - maybe with a flash format. This would allow us to conceivably enter the Coliseum, and look at it the way it once looked to the Romans themselves, before they went and had it ruined (pun intended).
When you think about it, we have that digital recreation of the Coliseum on film, with Russell Crowe, where we see such detail as fabric canopies used for shading from the hot sun the days of the games. There are also film recreations for the Forum, and of other buildings with street-life in the Roman imperial ages that are not so historically informed. So I say, on with this one, it has some interesting possibilities if they push themselves to the limits of their historical sources. Rome was not built in a day, and there is much that could be gained by doing this sort of thing.