The Fed had no choice but to eliminate the '97, '98 & '99 rules because they are inconsistent with ESIGN and were therefore voided for new customers after 10/1/2000. A late burial is better than none at all.
At the moment you can stick with anything that complies with ESIGN plus your favorite interpretation of the 5 regs in question--provided you can get bank examiners to buy your opinions (or give up and leave you alone until the regs are clear.)
After 10/1/01 you're in the Twilight Zone. Even though they're not mandatory, nothing but the interim e-Regs will exist. Until new e-Regs are proposed, commented upon, reissued, and final, you'll still have to convince your friendly examiner that you aren't violating anything. You'll have to prove a negative unless you plan to comply with the interim e-Regs!
In the imortal words of Alice, "things are getting curiouser and curiouser!"