Replying to my own question, yes it is technically possible.

I wold however ask for some in this topic. What I'm trying to get is an application (or two separate apps, doesn't really matter) that will be able to output two streams (from fmradio and mic) separately (so some operations may be performed on them).

So far I'm trying to user fmradio and maemo-recorder to achieve this.
Running fmradio and setting Input Select (in alsamixer -c0) to Digital, let me hear both fm output and mic at the same time. The problem is that those are the same stream for the application, so I cannot manipulate them separately. With this setting, however, maemo-recorder is able to record only mic (without fm stream). What stuns me is that both fmradio (giving both mic and fm) and maemo-recorder (giving just mic) use pulsesrc in gstreamer.

Any ides how this (two separate streams) can be done?