Will webOS replace Windows on all of your smartphones?
Microsoft will continue and will always be a huge strategic partner for Hewlett-Packard. Our focus is to create choice for customers around those products and services that will allow them to connect to the information they need as quickly and as safely as they can.
via HP Gets Its Hands on Palm – BusinessWeek.
Sounds like a definite non-answer. My bet is that they have not decided but that when they will decide it will be to show Microsoft the door.