I would guess this is their attempt at going after the virtualization market. They bought Sun for the hardware(among other things) so now they need the software. VMware was probably too expensive for them.

VirtualBox is not in the same playing field as VMware but it does work well and is popular etc. The team already knows how to build virtualization software. To me they're just missing some management tools.

Big companies like Google and Oracle don't really think about what's coming next year. Sometimes they invest in something that will pay off big in 10 years. I think this is one of those deals.

This is pure guesswork obviously. I have no idea...