just the other day, I handled the PEN. I know a lot of people are excited about this new format and the market has spoken. However, to me, the form factor is neither here nor there. As a carry with you anywhere camera, a point and shoot form factor is much more convenient and portable, and gives you the same picture quality in good light.
Once you go on to tougher situations, ie. birding, or sports, the big zoom lens comes out and no way the big lens will match that puny body, you'll need a DSLR body for those big lens, and fast phase detect auto focus speed.
So, in tough situations, and exceptional IQ, the DSLR is called in (here I equate exceptional IQ to exceptional HG and above lens). For everyday snapshots, the small pocket size point and shoot cameras are used. That leaves the PEN for......???