Warren,
No doubt we will see hordes of fly-by-night deck builders and sealers appear using scare tactics to get people to tear down there CCA lumber deck and build a new one or talking them into sealing jobs, at inflated prices. And the sad thing is, There will be a lot of people fall for it and get ripped off, giving the honest deck building and restoration companies a bad rap. If you are going to market sealing treated decks, do it quick before the roaches start crawling out from under their rocks and give everyone a bad name.
On a personal note, I was glad to see the EPA's decision to phase it out, should have been done years ago. About 10 years ago I read that the arsenic can leach out over time and that it can be absorbed thru the skin or accidentally ingested by handling CCA treated wood then eating something, or touching you mouth before washing your hands. When I was in my early 20's I got a mild case of arsenic poisoning, from drinking untreated water from a mountain stream. If you have never had it, trust me, you don't want it. Imagine the worst stomach flu you have ever had and then multiply the effects by 10, plus passing out along with it. Then imagine having it for 4 days, nothing stays down, not even water. No fun at all, and that was a very mild case. Needless to say I haven't bought a CCA treated piece of lumber in years, even try to avoid handling it without disposable gloves. As for using scare tactics to sell a sealing job, not me. If it's CCA treated, they can find someone else. Arsenic poisoning, Been there, Done that, Didn't like the puke stained tee shirt.