Both are good camera? No, Panasonic GH2 is a flagship or mother of all four third sensor camera, Better Images quality, Video mode etc etc., Read the specification comparison below and decide yourself before you buy your first 4/3 camera..
Best part of Panasonic GH2 is its higher resolution and multi-aspect sensor that doesn’t crop images, better ISO sensitivity and Dynamic range than Olympus E-PL2, Full HD video and Built-in EVF. The GH2 autofocus is more fast compared to E-PL2 and GH2 comes with fast burst shooting of 5 frames per second, the Touch focus shooting feature of GH2 is a unique feature.
Best part of Olympus is built in image stabilization, makes it much easier to use it with the huge range of lenses with or without IS feature.
Conclusion – Panasonic GH2 comes with more megapixel, more Dynamic range, ISO range, AF points and better Video mode compared to Olympus E-PL2
Quality comes with Price
Panasonic GH2 Price in USA $999.95 at Amazon and B&H
Panasonic GH2 Price in UK £1,199.99 at Amazon UK
Olympus PEN E-PL2 Price in USA $553.92 at Amazon
Olympus PEN E-PL2 Price in UK £474.37 at Amazon UK