Obviously, they have to sell lots of systems of this size to pay back what has to be a considerably larger R&D investment than they have even with Galaxy.
Sun has given a speed boost to its installed base as the company focuses on x64 systems and the forthcoming Niagara processor,
It's a local company with some useful code, engineers who obviously have skills and background and experience in the type of systems management that HP has. We don't know the terms of the deal, but it probably was not all that expensive. It looks to be a good deal for HP.