This is common. About 1 bike in 30 is leaking and needs a new tank, and there are NO MORE replacement tanks. They are supposed to be stocked in regional warehouses, but the supply has been used up because Suzuki underestimated the number of bikes needing tanks. Some dealers are still under the impression they can get the tanks in a couple days, but when they actually order one they are told that the tanks are on backorder with no scheduled ship date. If the customer complains, the dealer is given a phone number in California (not even toll-free!) to call where customer service will talk nice and promise to expedite your tanks and put you on the top of the list. BS! They tell this to EVERYONE!!!
Suzuki USA corporate says it will be about three weeks for shipping across the Pacific once the tanks are made, but they do not yet have a manufacture date from the vendor...so the wait will be AT LEAST another 3 weeks. Could be quite a bit longer. They will not hazard a guess as to exactly how long it will be: 30 days? 90 days? They won't say.
By law, Suzuki had to send out the recall notice as soon as they knew there was a problem, even though they were not prepared to replace the tanks, so it is not entirely their fault. But they should rush the vendor, or find another, and expedite shipping.