The response from publishers to this must be to license their information more broadly. If they don't, they risk isolating their content. It will no longer be part of the information infrastructure, and other publishers will begin to create competitive products. There are other dangers in not licensing information. Many users are not going to wade through multiple screens from separate publishers to get to the information they need.
Convenience often beats out quality.
In the past, licensing data was viewed askance by publishers who had their own Web sites. The risks of cannibalization were too high to offset the potential benefits. In the Web world, this need not be the case. One of the virtues of electronic data is that it can be reshaped in hundreds of different ways. Yet another aspect of the need to license is that in the electronic world there is unlikely to be the profusion of different reference titles that exist in the print world.