The only real big news has been the lack of a qualifying offer to Edwin Jackson. You only don't make a qualifying offer to Jackson if you are afraid he will agree to it. You are only afraid he'll agree to it if you have what you believe to be better plans for his position. What could those plans be? Here are my guesses from most to least likely :
The Nats are looking to deal for a young pitcher. Rizzo likes his pitchers like he likes his coffee; cheap, young and in team control for several years (that analogy makes sense, right?). The Jackson signing last year made sense with Strasburg's situation as it was. They needed to be sure of getting the innings. This year that isn't the case. The Nats have some chips to deal. If they want to get better on D, Morse is an obvious one. Espinosa could be one depending on how much they love Rendon. Or else their somewhat decently showcased "other" young guys like Moore and Lombo could be part of a package.
The Nats have a killer 1-3 and a 4 in Detwiler who might be very good as well. Taking a risk on a young arm is something this team can afford and is in line with their philosophy.
The Nats are looking to showcase Lannan and/or Maya. This wouldn't be popular with the Nats fans, but it makes sense to me. Lannan has been nothing but decent pitching for years now. The guy would be more than fine as this team's 5th starter and would be ready to be dealt early to another squad. If you don't let him pitch for a deal, it would be a waste as he'll just walk as a FA next year.
As for Maya, his age doesn't necessarily lend himself to be part of the Nats future but he did pitch better than Lannan did in AAA. Plus he's a complete Rizzo guy and I bet it gnaws at Mike constantly that this didn't work out. Throw him out there hope that he's great like you thought. If he's merely good that's still fine, you can deal him for something.
This move would allow the Nats all the monetary flexibility they need to really step up and make a big $ FA signing for the offense, where they seem more agreeable to such things.
The Nats are looking to sign a long-term pitcher. I don't see the Nats as being the types to sign long-term pitching but there is one guy (Greinke) who is good enough and young enough that you might try it. They did go after him before. My issue with this move is that for anyone other than Zack this hardly makes sense and what if you don't get him? You let a very good pitcher walk for no compensation for nothing? This is a big gamble that I don't really think the Nats are making being pennant contenders now and Rizzo being the draft pick hoarder he is.
The Nats are looking to sign another temporary pitcher. If this was the case I don't see why they wouldn't just offer the spot up to Edwin. I don't see anyone out there THAT much better, but they know more than I do about Jackson, obviously, so I suppose this is possible. They liked this set-up they just didn't like Edwin for some reason.
The Nats want to keep the 5th spot free to showcase their young pitching just like Detwiler last year. That would be nice but who would these young studs be? Meyer is the best bet, but he'll open the season in AA. I can't see him up early enough to be the driver of a 2013 plan.