Tom Warren, writing on The Verge, reports that sources familiar with Microsoft's plans for Windows Phone 8 have indicated that FM radio functionality will be making a return to the platform as part an upcoming platform update (GDR2). All current Windows Phone 8 devices have FM radio hardware as part of the Qualcomm system-on-a-chip (SoC), but the hardware must also be connected to an aerial (usually done via the 3.5mm audio jack), which is likely to determine exactly which devices get FM Radio support.
Support for FM Radio will be enabled by the addition of the necessary drivers and, in all likelihood, an update to Music+Videos app. The necessary software was present in previous versions of Windows Phone, but did not make the jump to Windows Phone 8, likely to due to time constraints during development. While FM radio is being replaced by streaming services in some markets, it is still considered a desirable feature in a number of markets (e.g. India).
The Verge also indicate that Nokia is working on its own firmware update that will go alongside the GDR 2 update. It is anticipated that this firmware will include support for colour profiles, a flip to silence option (i.e. for incoming calls and alarms), and an option to have a double tap on the screen wake-up (unlock) the device. This double-tap-to-wake functionality was one of a number of much admired features on the MeeGo powered Nokia N9 and would provide an alternative to the dedicated lock/power key.
We've previously written about the colour profile support here. It's part of an update to the display+touch module of the Settings app:
This colour profile functionality would be similar to that found in TVs and computer monitors and would be used to customise the display output to an individuals preference. For example, some people prefer warm and vivid colours, while others prefer to have a screen that displays colour as accurately as possible (and this can vary from person to person as we don't all see things the same way).
Flip-to-silence functionality was first added to Windows Phone by HTC in its Windows Phone 7.x devices. Nokia followed suit with its Windows Phone 7.5 Lumia devices, but the feature is currently not present in Lumia devices running Windows Phone 8.
The firmware is also expected to contain a number of stability improvements and performance enhancements.
Neither Microsoft or Nokia have officially acknowledged the GDR2 or associated firmware update specifically, but it's clear both companies have on-going work related to software updates for Windows Phone 8 devices. The GDR2 update is expected to be similar in scale to the GDR1 (Nokia PR 1.1) update (i.e. relatively minor) and is expected to start rolling out in late spring or early summer.