If you like the articulating monitor, you've probably got the best. I got one last year, and was disappointed with the monitor. All I could see was my reflection. That ain't pretty!
I had to pull the trigger on a D7000. Couldn't wait for the bugs to get worked out of & the availability to resolve for the D800. I need something that I can really learn to use that is past the bug stage in time to use all summer as I travel. I also needed something for a wedding shoot on 5/5/2012.
I'm expecting a D7200 announcement before the end of the year.
I expect the D5200 & D7200 to have 24MP, and a better high-end video. It's possible that the battery problem is holding up the availability of the D800, and the introduction of the D7200. But what do I know?
Enjoy the D5100. I got some good shots of Balds & Bears in Alaska last summer with mine.