Since Google is transitioning to a buttonless style OS with Honeycomb and Ice Cream Sandwich, it isn't a shock they are telling developers to move their menu functions to the action bar. All phones up to this point have a dedicated menu button, but that won't be the case moving forward. Google has instituted an action bar that includes the three dots that work as the new Menu.
The problem with some apps is they're still pointing towards a physical menu button and since Ice Cream Sandwich, and particularly the Galaxy Nexus, doesn't have a dedicated menu button, the system shifts the three dot action overflow button beside the system navigation. Normally this is on top.
According to Google, this is doesn't provide an ideal user experience. I will say that for me personally, I have noticed the action button moving from top to bottom (and vice versa) between apps, and it's a little annoying. Google recently posted instructions for developers on how to migrate to the action bar or remove it all together. Hit the source link to find out more.
[via android developers blog]
