Quite a few people think that - now that they are out of office - it is too late to try Bush, Cheney, Rumsfeld, Gonzales and the rest of the boys for their crimes.
Even those who support prosecutions think it probably won't happen. For example, Dave Lindorff wrote today:
The likelihood of their being indicted and brought to trial now that they have left office is exceedingly slim.
The truth, however, is that it is a much better time to prosecute the criminals then when they were in office.