It looks like 20x is the new 18x as Olympus incorporates the f2.8-4.5 26-520mm-equivalent lens from its top-of-the-line SP-570 UZ into the SP-565 UZ, which replaces the popular SP-560 UZ. Otherwise, it's identical to its predecessor. The advantage of this model is that it doesn't have the irritating zoom ring that's on the SP-570, but it also lacks a hot shoe. And I suspect the disappointing performance remains unchanged as well.
The SP-565 UZ is slated to ship in October for $399.99.