Camera Suggestions for Street Photography

I'm a passionate photographer living in NYC.  I shoot with an Olympus E-30 using 4 lenses: 14-54, 9-18, 50-200, and 50MM.  My camera is almost 3 years old.  Olympus has basically abandoned 4/3's customers in favor of micro four thirds, even though there are vague pronouncements about a new micro four thirds camera coming at the end of the year that will properly focus four thirds lenses without camera lag.  Since I don't think I would get much for my equipment on a trade in, I'll probably hold onto my gear.

So with the sensor advancements made over the last several years, I've been thinking about buying a second system.  The shortcomings of my present system are:

1.) Olympus four thirds DSLR's were never good in low light situations.

2.) I would probably prefer a noiseless shutter as the clicking noise attracts undue attention on the street.

3.) A smaller footprint also attracts less attention and is less intimidating for street photography.

4.) Olympus DSLR's were never good at creative selective focus.

Any thoughts or real life experience with camera gear for street photography is much appreciated.