2013-04-30-03-09-41-mozilla-central-firefox-23.0a1.en-US.linux-x86_64 bug 748894 has moved the star button outside of the location bar. Not just outside, but behind the search bar. But starring refers to the current location, not to a search. So it is more intuitive and convenient to have the button near the address bar, so you can easier see what you are bookmarking. Not only is the button in a "wrong" place by default, but comments in that bug say it is going to be impossible to put the button between the two input fields!
starring refers to the current tab, whatever is in the content window, not to the location bar, indeed you can edit the location bar content and the star is still there (disabled for now, but that is likely to change). You are making this comment based on the previous situation, not on the current one.
Per design. You're free to move it elsewhere if you prefer.