for me (PR1.3, fmradio 2010.03.20, n900-fmrx-enabler 1.5-4+0m5) FM radio works as for earlier systems. One thing it cannot do: Let me listen via Bluetooth stereo headset while using the physical headset purely as antenna. This combination does not work, with funny results like routing the N900 internal mic to the Bluetooth headset while at the same time using the wired headset as antenna for FM radio, which can tune in and display radio text, but then no sound output...