I strongly suspect it's just a matter of time until all lead is banned everywhere in the USA for use as sinkers or fly weight. Bet by 2020 it will be a reality. Definitely will make the Euro style weighted fly fishing tougher in some instances. I've yet to see a practical wire substitute for lead that actually is heavy- tin is something like 60-70% as heavy- I think. Tungsten beads certainly help a lot, and combined with tine wire are usually more than enough to get the job done. You can always oversize your bead if you need a really heavy fly.