Assuming a rational market (see below for disclaimer!), the E-series could do well, at least in the consumer SLR market to start with, so long as the price/quality looks good relative to the options just above and below it, so let me try to estimate pricing.
I would expect that a high end consumer level E-series body (maybe not the magnesium clad first offering) should be possible at several hundred less than the Canon 10D due to smaller sensor cost, so say $1300, and the standard lens should be no more than $250 (Canon 28-105 price), so a total negligibly more than I currently see for the E-20N, and with the appearance at least of being a far better camera for the moderately serious amateur.
But might not such customers then make the next step up to a "half-frame" DSLR with Canon, Nikon or Pentax lens compatability?
Right now, the price and convenience gap is big enough to stop many amateurs from taking that next step, largely due to the need to buy and carry a second relatively expensive ultra-wide zoom in order to get only moderate wide angle coverage, and really big money to get a lens with ultra-wide zoom coverage like the Nikon 12-24mm. (Down in the consumer camera world, $1200 is way to much for a lens, especially when it is so specialized.)
Things will get better soon for half-frame in the consumer DSLR market if the rumor is true of a second Nikon DX lens that is about 18-70mm, giving the FOV of 28-105 in 35mm format. Such a wide ranging zoom will probably also have a little mentioned side benefit: it could be somewhat useful with 35mm format too, because vignetting apparently only occurs when you exceed the angular FOV limit, which is 28mm for 35mm. So the lens would still work as a 28-70mm on a 35mm body. That would be useful at least for those who want to carry both film and digital SLR bodies for the time being.
About assuming a "rational market" though: a major threat to 4/3 format is the "SUV fallacy" of buying into far more capacity than you are ever likely to need, whether it be wanting 11MP and up even though you will never go beyond 8"x10" or standard inkjet size prints, or wanting access to a range of seventy lenses even if in fact the initial Olympus E-series line of four lenses already covers what 99% of consumer SLR users ever buy, and adding a wider zoom would make it about 99.9%.