Just read the indictment (43 pages). I recommend reading it. I believe they have less on Bob and more on Maureen, and the theory around here is he rejected the offered plea deal because he thinks he can beat it but in the process it won't go so well for her. So much for marital harmony.
From what I understand, it's not illegal to receive gifts as a VA pol, but it is illegal to return the favor via a quid pro quo. So in a nutshell, the McDonnells are deep in credit card debt and have under water properties in VA Beach (sounds like Maureen has serious spending issues). Wouldn't be surprised if there is a divorce and bankruptcy in their futures. It's a shame for him because ex govs usually land cushy jobs at big firms (I don't think George Allen was at McGuire Woods for his legal acumen). And now he likely won't get that opportunity. From what I've heard he wasn't a bad guy to work with - was certainly no Kookinelli. As for Maureen, I think she's going down, and this process will not be flattering to her. Whoever is doing their criminal defenses should make sure they get paid up front.