I've leased a lot of vehicles in my day, including my new Silverado. Between the rebates and the dealer discounts, they lease very well.
This is a good deal. You are getting more than 10% dealer discount on the truck plus a 2500 rebate. That's a pretty steep discount for a lease.
For reference, any time you can get a vehicle with minimum down payments and have the monthly payment for a 36/39 month lease be at or below 1% of the MSRP per month, it's a good deal. In this case MSRP is about 49K. So 490 and below per month is a good deal.
I would recommend looking at the 36 month numbers instead of 39. Reason being that you wont have to pay registration for the 4th time. Here in CA that is a big expense. The price should be very close to these numbers.
For reference, my High Country was MSRP 65k and I leased it for 519+tax with 12k miles. You are in the same ballpark with the relative vehicle prices.