I predict it will disappear when Robert Scott no longer has any influence, which will probably be a result of his death, and that will be unfortunate. I don't mean any malice toward him. He is the man who bought and rescued S&W in 2001. He also oversaw a tremendous turnaround that was driven by the diversification of S&W's products and markets, helped by market forces that were the result of tragedies like Sandy Hook and political conditions. He was originally the CEO of Saf-T-Hammer, a gun lock company, and when he bought S&W, he vowed to apply its product/design to S&W's products as it made sense. The revolver lock is the only thing that became of this and I believe it is to him his signature legacy.
Bob is currently 73 and not likely to soon give up a substantial stake in S&W even as it prepares to spin-off from AOBC (the current name of Saf-T-Hammer Corporation). It is probably reasonable to imagine he will not be around 30 years from now, and then there will be no one on the board of directors with any affinity to the "lock." I do not believe the concerns about the liability of removing it are unsurmountable.
S&W only competes in the double-action revolver market. They don't compete with Ruger or Magnum Research or FA in the single actions. Within the DA market, they dominate in every segment they want to. I'm sure they're happy to let the import brands possess the low-price segment. Ruger is just now beginning to enter the competition segment with their Custom Shop 9mm Super GP-100. They have a long way to go before competitors are going to switch to Ruger for no other consideration than the "lock." The Kimber and LCR have been eating into S&W's dominance in the "J frame" segment, but S&W already offers several models of the J frame without a lock, so there is nothing to be done there. S&W is competitive in the DA hunting revolver market, but this is really only a portion of the overall hunting revolver market, a large portion of which is made up of single actions. If S&W wanted more market share in hunting revolvers, they would be better off introducing a single-action than they would be deleting the "lock." That move would most certainly sell more units.
The only segment where I see a legitimate concern for lock-equipped S&W's is the nostalgic "classic" market. There is no question the lock hole mars their line of blued "Classic" revolvers like the 29, 27, 57, 10, 19, 48, 36, 17, 25, etc. But up until now, they were really only competing with their own products on the used market. Now that Colt has introduced a classic-styled Python, there may be a little more presure on S&W, but when you consider the size of this segment, it can't amount to an irresistible force.
The Super-GP100 and the new Colt Python do put a modest amount of market pressure on S&W to remove the lock, but you must imagine those new guns have yet to produce any measurable effect in S&W's sales figures. They might look at responding by this time next year, but then again, the Super GP and Python could yet fizzle.