My Mrs has an NX1000 and while that particular camera is 'ok' the few lenses that there are in existence are corkers.
The 16mm f2.4, 30mm f2.0, 45mm f1.8 85mm f1.4 and 12-24mm are pretty much the only lenses I'd ever need on any system.
Having said that they are hard to come by and the NEX system has more readily available lenses and better support. The Fuji X system is also superb and has about the best image quality of any camera outside of a full frame sensor and also has some superb lenses but the video quality is gash and the AF while good is about the worst there is of any mirrorless (only the Canon EOS M is worse).
Personally I'd go for a NEX, they've got a nice balance between simple user friendly features mixed with some more advanced functions for the more serious tog,