I agree with everything Feppe said, including the suggestion that you wait a bit. Right now, the weak spot IMHO with the m4/3 is the sensor (in both Olympus and Panasonic.) They are pretty good, compared to film, but get blown away by the latest generation of sensors that we see in the Pentax K-5 and the Nikon D7000; and since the strong point of the m4/3 system is street shooting, a good high ISO sensor is pretty important. We may get it in the next generation (though I'm a bit skeptical; I expect some improvement, but not as much as would be ideal -- I don't expect them to approach the K-5.)
One problem with Oly lenses (in addition to the fact that most reviews say that the Panasonics are better) is that they rely on Olympus' in-body image stabilization (IBIS); so the lenses have no built-in stabilization. That means that Panny lenses on the Olympus are stabilized, but it doesn't work the other way around -- the Olympus lenses will not be stabilized on Panny bodies. As body designs leap-frog each other in the future, it'd be better to have Panny lenses that would work with both bodies, than Olympus lenses that will only work with Olympus.
Of course, YMMV: if you really are a hard-core street shooter and don't care much about longer lenses, the Olympus lenses are a bit smaller and less conspicuous than the Pannys. By the way, there are rumors that Olympus is about to produce a 4/3 "pro" body. But then, there are always rumors.
JC