The only two things I really miss from the D-SLR (in my case Canon gear), is  The near-instaneous AF, and  the off-camera flash options and functionality.
The strobist side of stuff was something I have only dabbled in thus far, but greatly want to explore more in the future. I want to more car photography again and start doing some portraiture, and my preference for these genres is with flash/strobist lighting as part of the mix.
To be honest though - the AF issue is a double-edged sword. With the faster AF of the D-SLR comes the (much) more imposing presence of the larger body, which pretty well defeats what I would want the better AF for anyway ('street' photography/portraits).
I still love the X-E1, it covers what I consider my 'recreational photography' perfectly (lanscapes, streetscapes, urban lifestyle, etc...), with great IQ and easy portability. Obviously not quite pocketable but so light it never really feels like a burden either.
Can't help noticing that niggling feeling that I want to build a Canon strobist kit though. Watch this space.