It's the littlest portrait lens I've ever seen. The lens cap is barely larger than a 2-£ coin.
Bokeh test at full opening. Very promising, though I have yet to test it in daylight.
Top image with noise reduction in software, lower one without. ISO 1600. Good result for a M4/3 sensor, the first full frame Canon 5D didn't do it all that much better. And nice soft bokeh (background blur).
By request, a comparison between Olympus 45mm F:1.8 and the great little Pentax 70mm F2.4. (For different formats, so the use is roughly the same.) Similar in bulk, the Pentax is shorter, but fatter. Slightly heavier (all metal), but in this class it hardly matters. The Pentax sits on a bigger camera (a DSLR), but also a more capable one, ultimately.