The plug-in worked in all the 6.7 betas right up until it shipped.
The plug-in works in the Flex client, but won't install in the HTML client.
Hoping that U1 will fix this issue.
The log file says:
Plugin package com.mycorp:1.2.0 was not deployed because attribute type="html" is missing, which is normal if this is a Flex plugin.
However, my plugin.xml file has:
<plugin id="com.mycorp.myplugin" moduleUri="mycorp-flex-${project.version}.swf"
defaultBundle="com_mycorp" type="html">