I'm in basically the same situation....and I have done the most disgusting amount of research trying to find the right answer. Conclusion: There is no right answer..
So.....for your purposes, which are nearly identical to mine, here is my novice to novice answer fwiw.
First: You have an 11,000 lb trailer whereas mine is 7,000 loaded, 5,500 dry. IMHO figure on loading and pulling no more than 80% of your max weight rating to stay safely within the "bringing enough truck" range. It's one thing to pull that much weight....and entirely another to try to stop it. I thought my 8600 GVWR Expedition EL coupled to my 7000 GVWR travel trailer was enough truck, and it feels like a Prius trying to pull a raging bull to a slaughterhouse. Lots of white knuckle driving in wind, but I admit, I didn't know too much about what I was doing and should have been a little slower in my first trailer pull trip.
I could be wrong and probably am according to many....but it sounds to me like the 2010, with a max trailer capacity of 13,000 lbs is on the edge of being too light for an easy pull of a, 11,000 lb trailer plus people in the truck, plus gear, plus fuel weight, plus water weight, plus wind load, you get my drift. Yes it WILL pull the trailer. Yes it will. A million other people here will tell you yes it will.....but its out there towards the end of what you SHOULD do if you like an easy trailering experience...again...IMHO..but the 2011 has a trailering capacity of 20,000 lbs!!!!
That being said, the 2011 will be a jump in GVWR and a jump in torque over the 2010. Torque is up at least 40 ftlbs; from 660 to reportedly somewhere north of 700. Ok so that's a LOT of torque, or a lot MORE torque. But you're apparently comfortable with the 2010 power per your statement so thats good for the 2010 option. Vote 2010..
The other biggie that the 2011 brings to the table is the electronic trailer sway control function. Yes, for under $1000 you can get a Reese dual cam sway control assembly and knock alot of sway down, but if that electronic sway control technology lives up to its hype, it is a BIG reason to wait for the 2011 with a 11,000 lb trailer. Mine sways like a flag behind my soon to be traded back 07 Expedition EL, so its a big factor to me. Vote 2011
I think it is reasonable to expect that you should be able to get a better deal on a 2010 in its last year of production over a 2011 in its first year of production, so if money is a consideration...Vote 2010
As for me.......................I'm probably going to buy the 2009 new old stock (identical to your 2010) that I have been eyeballing for a few weeks now. The 2011 is a much stouter truck, capable of hanging with all construction and oil field applications neck and neck with the F250.............but that's not what YOU and I are using our trucks for!!! You and I are looking for a good powerful now and then RV puller that has room for the family and manners sufficient to be a daily driver...........so in that case..........the somewhat lighter duty chassis of the 2009/2010 is MORE than sufficient to meet our needs and at a good price ideally.