Concerning the slowmotion feature,
I've found a very small application on Itunes for Iphone 3GS called "SLOMO"

This small application for Iphone, allow to transform an initial footage into a slowmotion footage directly on the Iphone device.
Of course the slowmotion can be enhanced, but this show a potential trend for new intagrated effects on a camera.

This sort of effects can give some ideas for Olympus engineers and marketing team in order to include that effects on the E-PL4.
If E-PL4 can reached 50i/s or 60i/s with 720p or 1080p in progressive mode the slowmotion effect could reach a real level of perfection.

Hoping the OLYMPUS marketing team will choose this trend.
This effects will surely be considered as a key criteria and may influence future buyers especially for people who hesitate between a CANON 550D, 600D ... only for its ability of doing slowmotion after post processing (see message above with video on youtube) due to the format CANON H.264