One of the things that always distinguished Canon and Nikon is the width of their DSLR product selections - you can get entry-level, midrange and professional DSLRs from both companies.
While Sony might arguably also offer cameras in each of those classes, I think Olympus is more purposefully positioning itself as a full-range provider. Their E-3 is geared to the pros at a street price of under $1.500, the E-52 is a crazy-cheap beginner DSLR at $499, and the new E30 straddles the fence with a list price of $1,299.
With the E-3 selling for $1,429 on Amazon, the E30 better street at less than $1,299 if Olympus expects anyone to buy it over its barely-more-expensive big brother.
One thing I love about the Olympus's (Olympi?) are the articulating LCD's. While I don't have much use for Live View on DLSRs, a rotating screen makes it much more usable for over the head Hail Mary shots and knee level macros and baby shoots.