I'm a week behind, buuuuut given that last week's ep ended with [spoiler]Osha taking Bran and Rickon away without the Reeds ever showing up[/spoiler], it's entirely possible that the Reeds won't be in the show at all, which would mean a vastly expanded role for Osha and go some way to explaining Asha's name change.
I suspect that will really fuck with the way things play out in books six and seven, buuuuuuut honestly taking out the Reeds and (book two ending spoilers) [spoiler]the separation of Bran and Rickon[/spoiler] wouldn't really have any major impact on anything that's happened up to this point.
More's the pity, really, because (book five spoilers) [spoiler]Davos going to search for Rickon and Osha[/spoiler] is the dangling plot point that frustrates me the most at this point.
Yes, more than all those other ones.
...though again, I'm a week behind, so for all I know Jojen and Meera just came bouncing down the road a couple days ago.
EDIT: Wait, I've got it.
Consider all spoiler-tagged stuff from here on in to be major spoilers for pretty much all the books up to this point.
I can see how the Reeds can be completely excised without any major changes to the story, because [spoiler]their purpose is twofold: one, they get Bran as far as the Wall, and two, they know the truth about Jon Snow's parentage.
We can really get around #1 once Coldhands shows up -- Osha and Rickon can go one way, while Coldhands, Bran, and Hodor go north of the Wall. So Osha and Rickon are hiding at whatever location is convenient for Davos to seek them out later on.
As for #2: well, we're all assuming Coldhands is Benjen Stark, right? I mean, I'm kinda hoping it's something less obvious, but that's where the smart money is. So he could easily know Ned's secret. Otherwise, you could just handwave Bran's Omniscient Tree Powers as a way of finding out. The Reeds are unnecessary.[/spoiler]
