When 1Password 4.2.x was released to our webstore customers, a few issues were detected. Our developers have managed to properly squash these bugs, so we've decided that the best course of action is to simply skip to the next release so that Mac App Store customers get the fixes to these issues, instead of having to work around them first.
We know that there are some nice improvements in 4.2 that you're all excited to see, and we sincerely apologize for the inconvenience here.
As usual, we can't comment on when the next version will be released, as there are too many factors involved, many of which (like Apple's review process) are completely beyond our control, but we are doing the best that we can to get it out to users just as soon as possible!
We very much appreciate your patience and understanding here.
Please feel free to contact our support team or open a new discussion here if you have any questions or concerns!
UPDATE: 1Password 4.3 has now been released at the Mac App Store!