By far the best set in the upcoming Tolkien line is 9474, The Battle of Helm's Deep. This will run you US$130, but for 1368 pieces and 8 figs, that's not too bad. Plus, and most excitingly IMO for builders, this is not dependent on large single-use pieces, but instead is a big box of bricks and plates.
I know some castle builders are unhappy that the upcoming Tolkien line seems to be putting a more traditional non-licensed Castle theme on hold for a while (as the Star Wars theme displaced the non-licensed Space theme for a time, or, for that matter, as the Harry Potter theme displaced Castle for a couple of years), but I think this set shows that licensed themes are nothing to fear (okay, I know some will not get over the use of fleshy-figs). Even if you're not a Tolkien fan, this rocks as a basic castle. For instance, look at the detail in the wall construction.
There is a little bit of interior detail, so this isn't all facade.
Here we see some nice detail, like how the hoarding has shutters and machicolations. The merlons should maybe be a brick taller, but that's easily modified.
Here we see the sally port that Aragorn and Gimli used, and a little catapult that you can use to (sigh) toss a dwarf. Why, Peter Jackson?
This is supposed to be Haldir. I'll pretend that it's Legolas and he just got a new outfit at Meduseld.
Theoden looks pretty darn awesome.
As does Gimli.
Here we see some Uruk detail (meh, IMO).
You know, I would have expected there to be an 'action feature' with the wall blowing up, but it wasn't mentioned in the Toy Fair video. If those are tiles atop the arch, maybe the wall comes apart into three pieces here. Or maybe that's just an artifact of how it is constructed (if so, I'd probably modify this bit, as that vertical crack is noticable).
With four figs on each side of the battle, a rearing horse, and some detail like this siege ladder, this set has a ton of play value.
All in all, this is an amazing set, both for the Tolkien fan and also for the general Castle builder. If you were only planning on getting a couple of sets from this line, I'd go with this one, and also Gandalf's cart (since it's cheap and you get two key figs).