It doesn't say anything at all about HP making hardware. It just says they'll continue to evolve and support the OS.
If other manufacturers jump on webOS because it's now completely free (no strings attached) and a very polished and slick OS, then I'd bet HP would start making devices again. This way, others can grow the platform into something popular enough that HP might want to make hardware again. We'll have to see if Acer, Asus, Samsung and others decide to make webOS tablets or smartphones in the future.