If yer caning the pants off it in the twisties or spend all your time in heavy traffic/cities, then expect low to mid 30s.
If you spend some time on the freeways and some in the twisties, then low 40s.
If you ride like a gramma and never come out of ECO mode then low 50s is possible.
If you really care about gas mileage, then you probably bought the wrong bike, unless you came from a ZX11 or Z1300.
Motorcycle magazine testers thrash the crap out of their bikes much like the rest of us do with rental cars.
I used to average about 44Mpg(UK) = 37Mpg(US) when commuting. My 08 model does not have ECO mode.
About half of my commute was at 40-80Mph on motorways mostly at constant-ish speeds, and the other half was 20-70 on twisty backroads where you are on and off the throttle and almost always accelerating, braking, or turning.
Now that I am no longer commuting by bike, it's now ALL twisties and my gas mileage has dropped considerably to 37Mpg(UK) = 31Mpg(US) despite running the MRP flash and running on 98RON gas (93.5 US Octane).
My best ever mileage was a whole tank at between 50 and 70mph and I got 48Mpg(UK) = 40Mpg(US). It was REALLY boring though.