Olympus users have long wanted to see Olympus return to their glory days during the 1970's-80's when they innovated and revolutionized cameras. Today Oly is known more for its late entry, copy-catism and poor marketing especially in the US.
I believe the OM-D is Olympus' last and best chance to re-establish itself as a leader. Clearly the timing of this release is excellent since the market is infatuated with retro-looking bodies. Oly's products have always been good but the biggest issue is image quality especially at higher ISO's. I purchased my E-3 because of the in-body image stabilization and to leverage my investment in older Zuiko OM glass. It's an amazing camera but for high ISO, it clearly falls behind Canon and Nikon. If the OM-D can shoot well in low light situations, I think it will be accepted in the market.
My biggest fear is that if this camera is a smash, Oly will "rest on its laurels" like it did on the original OM series. Innovation is the key to success.