In reply to cousin nick:
What ever you do, ride as many bikes as you can on test rides. This may cost you a bit (my local spesh dealer charged £50 a go), but normally if you end up buying they take the money off again, and even if they don't it is well worth it in the long run.
Spread your net far and wide in terms of makes, and don't place too much confidence in magazine reviews - e.g. I've never seen a "this bike is awful" review, but there are definitely some awful bikes out there.
It sounds very much to me like your style of riding tedns to teh XC end, and as such 140mm travel is probably the most you'll want, and probably will only need 120mm (you would be amazed at what a good 120mm XC bike can cope with - I rode most of the Snowdon ranger track on mine, but then you already know this to an extent if you are riding a hardtail)
At 5'11" you are on the borderline for 29rs vs 26rs, and I would stongly advise trying to test both sizes back to back (preferably by the same manufacturer and similar spec) some people like them, others don't. From my experience of testing Specialized epics back to back, there were obvious differences - the 29r was quicker on straights, good over uneven surfaces, and seemed to roll over obstacles much easier, however it was slower to react, required more precision entering corners(less ability to correct your line mid way through a corner if you got it wrong), and slower on twisty stuff. It also suffered from being heavier, slower to accelerate and a higher centre of gravity. Overall I went for a 26" machine as it felt like more fun, and I wasn't in it for pure pace. (I would still like one at some point, but alongside my 26r for different riding).
Oh, and don't be swayed into buying a bike that has a dropper seatpost speced if it's not right for you, you can always add one later as I did.
If you act quickly you may still be able to get your self a 2012 bike at a good discount and get even more for your money
Some other bikes for you to consider (XC focussed to start, moving to more "All mountain)
Cannondale Scalpel - stupidly light (22lb for the"2"), but more of a soft tail than full sus
Specialized Epic 26" (not sure they still do these as 26) short travel but capable xc machine. Brain takes a while to get used to.
Lapierre X-Flow (what I bought in the end - lightening quick up hill for full sus, but plenty of control on steep and technical stuff the carbon frames come in about 25lb - not the easiest to find though)
Cube AMS 110 - looked great in the shop, good spec for the money, but it just didn't ride right for me.
Specialized Stumpjumper - It's been around for a while for a reason, very nice bike, but for me a little too much bounce
Mondraker Foxy - Good traction, not too much pedal bob and feels like its built to last, but a bit too heavy for the money
Lapierre Zesty - riot of a machine, but a little too much pedal bob when climbing for my liking
Whyte 146s - Amazingly confidence inspiring on the rough stuff despite being only 140mm - my friend complains about his front end being light when climbing and it does bob a fair bit even with propedal on
Orange 5 - A lot of people swear by these, but it didn't grab me, just felt a bit agricultural, and a little heavy for the money, undoubtedly a capable machine though, and you wouldn't be afraid of crashing it.
Hope this helps... here's the thread when I asked for advice back in August too:
http://www.ukhillwalking.com/forums/t.php?t=500933