I can't see D&D removing levels anytime soon, if ever. There's no real need -- a DM can scale any prewritten module to match the power level of the party with relative ease. B2 not difficult enough? No problem. Just change it to "Keep Far, Far Away from the Borderlands -- There's a Tarrasque...
Small point of order: Chainmail is a booklet. There's no box. You can usually find a copy or two on eBay for a reasonable price. I highly recommend picking up a copy.