Adobe's much maligned reading app for Windows got an update this week. It's now officially in to 2.0 and out of the beta testing which Adobe had been running for the past year or so.
I don't have a full update list for the current release, so I cannot say for sure if it supports some much desired features like Epub3, but I do know that a previous update added support for Japanese text. And from the release notes I can see that not all text styles are support (right to left, overprint, and others) nor does this app support embedded audio and video.
My source is reporting that the app has better support for fonts, and it appears that this app no longer needs to have fonts embedded in the Epub for them to work. There are also a number of bugs mentioned in the release notes, so you might want to read up before you download the update from Adobe.