Interesting - I’ve noticed that Embracer and Monologue are still listed on the Steinberg site as instruments included with Cubase 6, but they’ve gone missing for me as well. I’ll dig out my C5 discs.
Just noticed that they’re both present in the VSTplugins/synth folder of the Cubase 6.app, but this folder isn’t showing in the Plug-in Information list. 
No word from Steinberg on this subject yet?
Just got a copy of Cubase 6 and I encounter the same missing plugins, even being both present on the folder inside the app.
Edit: 6.0.2 btw.
You need to get the VSTBridge re-installed. That is done with the help of Rosetta.
I had the same problem. Embrace and Monologue disappeared. Reinstalled Cubase 6 and when trying to open Embrace and window came up and asked me to install the VST bridge. Clicked OK. All working now
I am using OSX 10.6.7
Hey thanks for the tip!
It’s a shame there´s no Rosetta on 10.7 any more, it seems we will lose them any way 
Seems to me its another way of getting you to spend more money and most probably to get rid of the bootleg versions of various apps that are around. You can bet for everyone app thats been bought there is a bootleg version !
This problem hasn’t been fixed for mac users yet, right? I recently upgraded from Cubase Elements 5 to Cubase 6.
I’m on version 6.0.5 - build 357, running 32-bit and Embracer and Monologue do not show up in my plug-ins list at all.
I can merely reiterate that they are showing for me, here.
As said before, try trashing the VST2plugins Blacklist.xml (in the Cubase Preferences folder).
If that doesn’t work, the “sledgehammer approach” would be to rebuild Cubase Preferences from scratch (making sure you have moved out of the way all Preference folders of earlier versions of Cubase, so that it will not try to simply re-import them).