Samsung seem to have learned their lessons from the past by trying to be innovative and progressive and different, now they are getting the nuts and bolts right, their alliance with pentax was phase 1 of this, the nx-10, probably the best camera of it's type on the market, is phase 2.
Both Samsung and Sony have opted for APS-C sensors rather than the significantly smaller four thirds size sensors. This means more pixels can be shoehorned on without the same noise, diffraction or pixel density problems.
As a new entrant to the market Samsung don't have the legacy of four thirds or micro four thirds lenses availble to those using the Panasonic or Olympus systems, even sony users can access alpha mount and Minolta dynax/maxxum lenses, albeit in manual focus only.
There is also the issue of branding. Samsung deserve the NX10 to be a success, but it's simply not as desirable a brand in camera terms as Canon, Nikon, Sony, Pentax, Olympus, Panasonic, Leica etc.
So although it's probably the best camera of it's type, presently, it is not the best system amongst the micro cameras.
SLRs such as the Canon EOS have a few benefits:
The EOS system is extensive, there are dozens and dozens of lenses to suit all needs and budgets.
As it has an optical viewfinder (as well as live view if you prefer the compact way of working) it can use fast phase detection AF. If you shoot sports or nature you want a camera with fast sensitive accurate AF. As the market stands only a DSLR can give you this.
The EOS system has been around for 20 years and will be around for years to come.
Unless you print beyond A3 the higher pixel count of the NX10 is of no practical benefit.