[Overtaxed]

I'm guessing they probably won't show it, but they may have Pippin and Merry talking about it. That's just my guess though.

...unless they do the old Republic Serial trick of changing the end of the previous episode.

[2Jedismom]

Well, you know right at the end, after Boromir gets the last arrow and is down on his knees...M and P pick up their swords and charge. Right then would be a good time to insert it...into the extended release.

[Bear_in_RoseBear]

Well, they wouldn't necessarily have to change then end, if we assume P & M were engaged in action we didn't see in FOTR... they could just change the point of view in TTT, so that this time we see what P & M are up to.