This isn't much of a deal, but the federal govenment recently extended the $300 tax credit for installing energy efficient appliances in your home. This had previously expired, so the deal wasn't as good. There is a $500 lifetime limit on this tax credit, so if you have filed a Form 5695 before, you'll need to figure that into the equation.
There may also be local utility company rebates and state tax credits. Check your rebates/credits by zipcode HERE.
In our case, we had purchased the water heater before the fed tax credit was renewed, but our state offered a credit and our utility company offered a rebate bringing the price down to roughly $400 out the door. With the fed tax credit renewed, we're now down to roughly $100 - not too bad. Plus, we're saving approximately $20 per month on our electric bill, so it will pay for itself in 5 months.
Federal Form 5695 PDF (this water heater falls under line 24a)
FWIW, the previous version of this water heater was made in Mexico and was prone to failure within 12-18 months. This is a redesigned version made in Louisville, KY. Hopefully, it is more dependable. So far, the reviews look good.
EDIT - Don't forget you can purchase through the cash back site of your choice for 3-5% extra back on the initial cost before rebates!