I finally use the E-PL3 with a Panasonic 20mm f1.7 lens and don't miss the flash at all. I carry the flash in it's little pouch in my pocket and if (if and when) I need it I have it in short order. As for the grip I just got a little "Flipbac" grip (same as I put on my XZ-1) and it works just fine. I also got the new VF-3 viewfinder and it's good to have once in a while on the E-PL3, but I really use it a lot on the XZ-1 which really benefits from it. I love the 40mm view of the Panasonic 20mm, but once in a while I need a different view and the 28-112mm of the XZ-1 is perfect. I carry both cameras at times and they both get remarkably good shots.
Much love, Sera