The HP Oracle hardware partnership is definitely not happy news for Sun, and Sun's ~$1B decision to acquire MySQL AB is perhaps not looking so brilliant at this point.
The major difference with this partnership involves Oracle’s decision to champion H.P. over its other close hardware partners like Sun and Dell. In the past, Oracle may very well have struck a deal like this with Sun, as Mr. Ellison has long counted Sun’s chairman, Scott McNealy, as both a personal friend and strong business ally.
Times have changed, however with HP’s server business growing while Sun’s declines. In addition, Sun acquired MySQL, a maker of open source database software that competes with Oracle.
For the Oracle/Dell partnership, I suspect it's only a matter of time -- as in the term of the HP exclusive in this context -- before Dell gets into the Oracle Exadata and Database Machine business. Given that Oracle has ~50% of the global DBMS market at this point, it'll be fascinating to see if IBM also jumps in, with Oracle-specific storage and server hardware.