I tried the NX10 over the weekend and I'm not sure about it. True it is better in some ways than m4/3 with better dynamic range, more detail, better ISO performance. It is comfortable to hold, seems easy to use, has a pleasing heft to it. But high ISO performance was not good (blotchy noise patterns), colors seem hard to manage (they are indeed intense by default!), and the lack of in-body IS was a problem at times (I guess I've grown used to it on my Olympus cameras). The Ricoh and Olympus JPGs and RAW files are both more pleasing and easier to work with. I was able to open the NX10 RAW files in LR3, but perhaps it does not have a profile yet. The NX10 seems to be good for B&W work and that was good to learn for my work. But I'm just not sure that it is the camera I am looking for.
The Ricoh GXR/A12 has become my gold standard serious compact and it's simply hard to be (except that it is currently limited to 50mms). And after a long hiatus I also shot with my Olympus E30 this weekend and was reminded why I liked it so much. Bigger and heavier, yes, but still easy to hold and carry. More and more to me it comes down to lens quality and the Ricoh A12 is phenomenal and the Olympus 12-60mm is stellar.
I will be curious to see what comes after the NX10. It's a good camera to be sure, but may not be for me just yet. But I'll be keeping an eye on where it's going.