Bryce Harper will come up on Saturday. Did he earn the promotion? No. Not at all. He had a decent past week but he's hit 1 homer in 20 games and he's getting killed against lefties. Is it bothersome that the kid is getting this handed to him without earning it? I guess. But really what it comes down to is how he performs when he's here. If he hits, no one will care unless he's a total ass. If he hits great. no one will care, period.
I'm not big on the whole "it's too early to bring the kid up" thing. If he's going to be good, he's going to be good. The important thing to remember, as far as I'm concerned, is that it's just money. Assuming the Nats didn't hold him down for a whole another year (which isn't necessarily a bad idea the way he's hitting, but then again it probably depresses team expectations for a few games in the key year of 2013), all this does is make him eligible for a Super 2. All that means is that the Nats will have to spend more money to keep him during his years before free agency.
This isn't a win NOW move. If they wanted to win more NOW, all stats say Tyler Moore would have helped the team more in the immediate future. What it is is an "let's get ready for 2013, and maybe we get lucky in 2012 move" and I don't see anything wrong with that. Didn't cost the Nats a year of Bryce. Just money.