I've just installed trusty with unity.
I press the win key for a while, but the shortcuts cheatsheet won't show up.
I tried with compiz-settings-manager and with ubuntu-tweaks with no luck at all.
Is there some way to see them? Whay has it changed the way it behaved?
I am experiencing the same issue and found the following solution:
http://ubuntuforums.org/showthread.php?t=2211817
Disabling workspaces brings back the cheatsheet (long pressing the super key). Not sure if you have it enabled though.