Here are my suggestions:
Clothing(carried)
Drop the extra T-shirt as you already have a Cap 1 camp/sleep shirt (-4.95oz)
DONE, ALSO FOUND A LIGHT MERINO SHIRT AT THE TS LAST WEEK, PROB REPLACE THE LESS VERSATILE CAP1.
Drop the towel as you already have a bandana (-2.19oz)
MIGHT REPLACE WITH A 2ND BANDANA, I LIKE TO HAVE A BLADDER SHOWER AFTER A HARD DAY. VERY REFRESHING.
Cooking
That weight seems like a large 8oz canister. You should be able to switch to a small 4oz
canister for short trips like that. A full small Snow Peak canister is 7.3oz (-4.36oz)
I'LL CONSIDER IT, PROBLEM IS I ALREADY HAVE THE BIGGER ONE, BUT ITS NOT LIKE MILK AND WILL GO BAD.
Hydration
I would drop the Steripen and go with Aquamira. Stock packaged Aquamira is 3oz, but can be repackaged in mini dropper bottles for a weight of 1.1oz and is plenty for that length trip. A prefilter isn’t normally needed on that AT but a bandana can be used if need be. (-8.79oz)
OK
I would replace the 2L bladder with 2 32oz Gatorade bottles. Bottles are lighter and easier to use and fill (IMO). Two 1L Gatorade bottles weigh 3.6oz. (-2.27oz)
HOW ABOUT I KEEP THE BLADDER AND DUMP THE NALGENE CANTEEN AND USE 1 BOTTLE. LIKE HAVING GATRORADE WITH MEALS (THE REASON I DONT USE A PLATY) AND DRINKING AS I WALK.
Sleeping
As others have said, a 40* bag might not be enough, but you have noted your contingency plan. I would just check the weather before you leave (adjusting for elevation) and make a game time decision.
OK
I am not sure what a Pillow Bladder is, but I have found that a sleeping bag stuff sack filled with raingear and extra clothes makes a great pillow (turn it inside out if clothes are wet are dirty, that way it doesn’t get your bag wet in the morning) or you can use your Nalgene soft sided container instead. (-2.54oz)
THE PILLOW BLADDER IS JUST THE BLADDER FROM A BLOWUP TRAVEL PILLOW, SAVING 1/2 THE WEIGHT THERE. I'M A SIDESLEEPER & HAVE HAVE NEVER FOUND A CLOTHES BAG PILLOW VERY COMFORTABLE.
Packing
Do you really need the string pack? (-1.34oz)
FOOD BAG, MAY SEE ABOUT REPLACING ALL THE SACKS WITH THE 4 PC SET FROM HYPERLITE
http://www.hyperlitemountaingear.com/products/accessories/cuben-fiber-stuff-sack-set.html
I see your sleeping bag weight includes a stuff sack, so what are the other two sil sacks for? I would leave them at home. (-2.05oz)
I would however add a Trash Compactor pack liner (+2.00oz)
Misc
I would replace the Leatherman with a Gerber micro LST (0.6oz), Spyderco Ladybug (0.6oz or a small Swiss Army Knife (0.7oz) (-4.63oz)
I HAVE A SMALLER MULTITOOL I CAN BRING SIMILAR TO THIS ONE.
http://www.amazon.com/Gerber-Legendary-Blades-22-41347-Little/dp/B002ZPMAII/ref=sr_1_41?ie=UTF8&s=hi&qid=1282760005&sr=1-41
i CARRY A TOOL VS A KNIFE AS IT SERVES AS MY POT GRABBER ALSO. I WAS BRINGING THE LARGER ONE TO CUT CHEESE, BUT I'LL MAKE DUE WITH THE SMALLER ONE.
You could probably cut your bear bag cord weight in half by switching to an Arborist Throw Line. (-1.00oz)
I'LL TRY DUMPING THE PLASTIC REEL IT CAME ON.
I have used Sil bottomed shelters for a long time and have never used a ground cloth or had a hole. Just make sure that you inspect the area quickly before throwing your shelter down. (-2.76oz)
ITS MOSTLY A SITPAD FOR BREAKS AND A PROTECTER FOR MY SLEEP PAD IN SHELTERS.
Conclusion
That is a net weight savings of 34.88oz all for little to no cost without any real loss of comfort or functionality.
I hope you have a great trip!