I think maybe we're underestimating allies. I mean, look at Radagast, you're going to want to keep him in play for a long time after you play him, he generates resouces and everything. And look at Haldir 4/2/2/2/3 he's as good as any hero! Better than some. Having someone as an ally makes them MORE versatile in a way than a hero, and you can have multiple copies of ones you really like in your deck, so they can be in play very frequently. I think we need to change our view of allies as less than.
Definitely lots of potential for an Ally who's in play- but getting them into play is tricky. As someone pointed out above, Core Set Gandlaf already prevents us from building towards a 3-player, 3-hero-each fellowship game. I hope that we're not going to be even more hamstrung and relying on lots of Hobbit-search cards to get Merry and Pippin out there too.
Never leave home without your Direwolf...
I like Bohemonds idea of getting two seperate games going. Because it's a co-op game, you could have two teams competing against each other doing the same scenarios, if you have two core sets. The customized decks would be different, so it could get pretty interesting that way!