As a scientist who wil be directly impacted by this, I will say that career-wise, it's a great boon to know you'll have funding in these times of budget crises and cuts. However, I'm in the camp that isn't sure "big science" is the way to go. Certainly there are advantages to it, but in many ways, these types of initiatives skew the focus of research and eliminate research for the sake of research, from which the majority of great findings arise. The most important things we've ever discovered didn't necessarily come because we were looking for it, but rather by accident so to speak from a tangential target.
Case in point -- PCR as we know it, one of the most fundamental and necessary tools of molecular biology was made possible by the discovery of Taq pol... which was found because somebody felt like looking at deep sea thermophiles.
Big science is useful, but not when it comes at the cost of independent research, which it often does. The human genome project is another example; it's honestly been tremendously useful, but nowhere near what was predicted when the initiative began. And it probably wouldn't even be here were it not for the efforts of a particular J. Craig Venter, who basically single-handedly beat the government.