Having listened to numerous seminars with Lisa Stevens and Erik Mona, Paizo will likely continue with their main strategy, as any good business model should, which is "plan for the worst, hope for the best." With the release of the Adventure Paths and the death of the magazines, they made contingencies for up to 75% of their subscriber base leaving them. With Pathfinder RPG, they only planned the main book and a few softcover supplements in the rules line at first, in case it wasn't sucessful. They always look to the rainy day in their strategy, and if it ends up better than this scenario, then it's gravy to them.
With 5E, they will likely not go gangbusters with some new system, or change their model yet; now, at 5E's release, I probably expect to see some new hardcover with a really cool subject matter or an eye-catching adventure path, just so the company and its fans can have something with a lot of buzz around it at release time. However, I think they will also want WotC to have success with 5E, as well. There are many friendships still there, and they are also canny enough to know that D&D, as a brand name, is still a tide that can raise all boats if it is successful.
Ignoring the die-hard segments, most of us gamers are still pretty wanton when it comes to other game systems, and if I saw an opportunity to play or run a good game with friends with 4E, Pathfinder, D&D Next, or savage worlds for that matter, I'd jump on board easily. I'll buy D&D Next, but it doesn't mean I quit buying or playing Pathfinder either.