CS has been through a couple of salary busts in the US previously though, no? One in the '80s when all the then-new CS programs started to release graduates into the market, then another after the dot-com bubble; or have I been misinformed?
This is nothing like the current environment, where there is a consistent demand for programming talent which outstrips the supply, and the industry as a whole is far more stable.
Of course, a global economic slowdown could put a damper on salary growth, but it will not be a salary "bust" like what happened after the dot com bubble.
Those are the companies driving up salaries — once that rollercoast ride stops I imagine that there are going to be mass layoffs and salary readjustments for years afterwards.
What seems more likely is that the little startups will get crushed as VC funding dries up.