Both cameras a good for what they are designed for. But, like anything else in life, there is no perfect solution. Each have their pros and cons.
Buy the camera that has the best performance in those situations that are most
important to you. If low light performance without flash is the major reason you want to upgrade from a P&S then get the Sony NEX-3.
The Olympus EPM1 is a good camera but it does not have superior low light performance vs the Sony NEX-3.
As for the Olympus' having a wider lens selection. I wouldn't put to too much emphasis on that. Granted, it is true, but the average user of these types of camera doesn't buy any additional lens because of cost.
I own an Olympus EP-2. I have approximately 8 different lenses for it. But, I know it's strengths and shooting in low light is not one of them.
At least not without making a lot of adjustments and using the proper lenses.
Last edited by zig-123; Jan 3, 2013 at 9:20 PM.