Yeah , remove this padlock?
Well, just from the looks of it, the seat could definately be changed to something lighter like Selle Italia SLR, or a Specialized Phenom, or a Fikik Arione or tundra if you want a little more comfort. Definately swap the tires out to some Schwable Rocket Ron, Racing Ralph, or Continental Race King, or Specialized Fast Trak or Renegade. And of course a new wheelset will give the most noticible weight loss but it will cost you more than all of the above suggested upgrades.
That is a pretty solid bike to be starting out in. That is also a very nice crankset you have there. In my opinion you are best to just save your money and do either of the following.
a.) Wait a bit, just ride and enjoy being on a bike while saving money. Wait to a year end closeout sale at a bike shop and buy the highest end bike you can find. Hopefully something with Sram X.X / X.O or XTR
b.) Buy a frame and peices each part one by one to save you the utmost weight you can.
To upgrade what you have now will basically mean replacing every single last component on the bike, right down to the fasteners. Is your money best served that way? I would say not. Will putting on an expensive super high end crankset on a bike targeted at a lower more affordable market transform the bike into a dream ride? Probably not.
A bike is more than a few parts here or there. It is a summation of all the parts. Parts matched based on fit/form/function. Buying a super light expensive crankset only to throw on heavy flat pedals is not an efficient way of using your money. You could have probably saved more money and saved more weight by just buying a XT crankset and buying Eggebeater SL pedals.
Right now the best bang for the buck for your bike to get quick improvement would be
Stans wheelset (pick one that is at your price point)
previous generation XTR M960 that are on closeout for many online bike shops
Continental RaceKing 2.2 Supersonic tires, or Schwalbe Racing Ralph 2.1
Control Tech bolt on skewers
XT rear cassette
used Selle Italia SLR saddles (there are a lot of used saddles on ebay and local craiglist, keep your eyes peeled)
Easton Monkeylite SL on closeout at JensonUSA for $65
But then you are basically piecing together an entire bike by replacing every single component.