I think Radio is not there...
But i am wondering why all people asks things that google never advertised...
The phone doesn't record on 720p, doesn't have radio etc etc...
We all must understand that Nexus S is most of a developer phone and google sell it to show what pure gingerbread can do....
So please to search reasons to buy or not....
All people asking for facillities that don't exist....
This is the phone....
If you want a phone to shoot 720p video, to have radio, to have led notification, to have metallic body etc etc, this isn't your phone...
If you want a phone with quick and very good support for Google and community, a phone with pure Android gingerbread, a full unlocked and Open Source phone to play with, then this phone is the only choice you have...
I am wondering why people jump in with non-responsive posts. People ask questions because they don't know something and haven't found the answer by other means (assuming they looked). How does a response like yours help move the conversation forward.
The phone has a thousand features in it, and only a couple of dozen advertised. Should we assume that the 900+ features that aren't advertised don't exist and therefore are a reason not to buy the phone.
The Nexus One hardware supported FM radio reception, but Google did not put it in there; we had to wait for the hackers to add it. See this
post.
It's certainly reasonable, in my opinion, to ask if the Nexus S, which many think is basically just a slightly modified Galaxy S (which supports FM radio) can do so, and if it's as simple as adding an apk from another Galaxy S device.
To the original poster, I don't know the answer, but if I were interested enough to do a little research, I'd google the ifixit teardown of the Nexus S, then see what radio chip it uses, and if that particular chip has FM radio capability. If it does, it's just a matter of time before some enterprising dev adds it in. Probably not as simple as installing an apk, there are most likely driver and/or kernel changes necessary to get it functioning.
edit: I see others have already looked that up. I've NEVER used FM radio on my N1 or SGS, but nice to know that it might be there someday, just in case.