We're working with Apple (along with others) to track down the root issue.
In the meantime, we've created a plug-in to do a manual override of the OS record/selection of the version of Photoshop to launch.
1) Download the plug-in from here:
http://adobe.ly/1Ef651i
2) Unzip the folder
3) Launch Lightroom and select File>Plug-In Manager...
4) Click [Add] to install the plug-in
5) Select File>Plug-In Extras>Select Photoshop for Edit in Photoshop...
6) Click [Select] and navigate to the versi...