Kapeli has released Switche (http://kapeli.com/switche/), an US$7.99 Mac OS X app that “combines CMD+Tab’s simplicity with Expose’s style and elegance.” In fact, it uses Expose for all of its features.
Users can define three pairs of keyboard shortcuts. CMD+Tab will cycle between active apps Expose-style and the other two pairs will switch between windows of the same app or between all windows. Switche can be used to: switch between applications; switch between windows, or switch between the windows of the frontmost application
The software can: skip applications with no open windows; automatically zoom windows (using Expose); and close windows and quit applications by pressing “W” or “Q.” Switche is a 2.3MB application that purportedly has no impact on the system.
It requires Mac OS X 10.6 (“Snow Leopard”). A demo is available for download.