I haven't heard anything specific on this, but I can't imagine PJ would pass on exploring the possibilities of those visuals, lol...
Well I have heard nasty rumours that the whole fight against the Corsairs is being left out, although it was mostly told in flashback in ROTK. I would think that it is easier to leave it in, to explain the absense of Aragorn and most of the Fellowship from most of the Siege of Gondor, and they have to be absent, or the whole plot structure is warped beyond recognition.
Bad enough that they are apparently leaving out the last quarter of ROTK. I have seen pre-movie analyses that the Scouring of the Shire is one of the main lessons of LOTR, the dreadful costs that must be borne by those who fight for the right, that much of what you are fighting for will still be damaged, though not totally beytond repair.