Actually, there is several proposals. One done by some of the best radio engineers in the biz proposed using TV RF 5 and 6 for FULL power FM stations..
create a new class and allow closer spacing on the new band than currently done on the current commercial band (2-3 channels or 400-600kHz apart for full power 100KW 2000ft Class Cs is 65miles....then 4 channels or 800kHz apart can be sitting on the same tower!! Go figure)
The AM idea is to move "Local AMs" like KOLE, 1450, etc (on the old Class C/backyard channels) to FM, delete lower power AMs and allow higher power on the remaining clear and regional channels....but it will be a hard fight on that one! (Of course the FCC is now allowing AMs to have FM translators...which is an oxymoron since a TRANSLATOR does NOT change the original signal in ANY way other than frequency....AM to FM?? Thats a retransmitter OR a LPFM)
There are soo few LD 5 and 6s left (Full power that is)......if they could clear the channels totally, then the full power plan would work...it could still work even with the limited number of DT stations if they placed the FMs away from the areas of the DTs...(of course given tropo on lowband, the DTs would get clobbered by FM carriers all over the 6 MHz wide range, not just one analog carrier as it was before June of last year (hard to believe its been one year as of this weekend since we said goodbye to full power analog TV)
Outside the US, I think in Japan the FM band goes down to 75 or so MHz...so they can manufacture radios that could cover 76MHz to 108MHz...but a lot of folks would have to get new radios to cover the new band....probably would make folks have to buy a HD FM radio....if that would happen, would be an excellent time for the FCC to mandate AMAX on the AM side of the radio....audio fidelity to 10kHz (where they roll off above 3 kHz or so), add DSP and/or Noise Blanker, CQUAM AM stereo mandated and AM could have a rebound...I SERIOUSLY doubt IBOC (the real name of HD Radio) will ever take hold on AM...a lot of stations have turned it OFF,,WLS in Chicago still operates in CQUAM stereo; they ran IBOC during the day for a while but at night, it would go off and CQUAM would come back on (you cannot run both at the same time).....Now they run CQUAM stereo all the time (on a talk station??? but I would love to hear MusicRadio back on the BIG89 with a decent radiio...actually I used to back in the 80s...WLS started with the KAHN stereo system...where the lower sideband was LEFT channel, the upper sideband was RIGHT channel and you heard it in mono on a normal AM radio....BUT the old tunable AMs (remember them??) you could one down and one above the main channel and get STEREO.....Leonard Kahn who came up with the system never allowed licensing of a IC chip that could decode his stereo system....the other competitors (Harris, Belar, Magnavox and Motorola) ended up either dropping out (Belar) or modifying their systems to be the same (Motorola won of course with their CQUAM -- Compatible QUadrature AM..involves both phase and amplitude changes)
AM stereo is different from FM stereo and takes much less bandwidth and was thought to be the savior of AM music stations...but the receivers still suck out there...I have a SONY XRA33 which can decode all the AM stereo systems and has a filter for narrow and wide....in the wide mode and listening to 790 AM KKBQ during the Q-ZOO days, it sounded better than the 92.9 KKBQ FM to me
and I listened to WLS In stereo at night whle they were still playing music....ahhhh the good old days...
Now with the DTV transition, some folks are looking at the low band TV channels for reuse as most stations have problems if they are on lowband...
oddly enough, there IS a LD3 in DFW that operates from Cedar Hill where all the TV and most FMs are and it covers the metroplex pretty well....one DT on a low channel out in Neb (???? I think) still covers as well or almost as good as their analog did...wellll as long as there is no lightning storms...then they are up the creek and SOL....will 2-6 go away?? Probably at least 5 and 6 will...with the guard band between 4 and 5 (72-76 MHz) 2-4 could remain DTV and 5+6 go FM expansion....time will tell......
(My fingers are getting tired!!