As written in the press release
The combination of HP’s global scale and financial strength with Palm’s unparalleled webOS platform will enhance HP’s ability to participate more aggressively in the fast-growing, highly profitable smartphone and connected mobile device markets. Palm’s unique webOS will allow HP to take advantage of features such as true multitasking and always up-to-date information sharing across applications.
As HP and Dell been competitors for ages, maybe this is the reaction to the leak that made it clear that Dell would be throwing themselves in to the smartphone market.
Personally I am looking forward more to the Dell Lightning than anything I can conceive HP-Palm to come up with.