Speculation is the first refurbished units go to fill the warranty-exchange stocks for in-store and online support in lieu of using new-production units. Once those stocks are built up, then they'll make refubs available on store.apple.com
If past performance is any indicator, it'll likely be August or so before they're available, and your savings will be $50 off MSRP.
Depending on your sales tax rate you'd do better to order a brand new unit from an out of state reseller such as B&H or J&R or similar. With 7% sales tax on a 32GB 4G LTE iPad, the cost difference between ordering one today from B&H or waiting for an Apple store refurb is $2.47 -- not worth waiting two months for that small a savings.