This is interesting because I looked on Oracle's website for the deal expecting to at least see a percursory promise to keep things open but didn't find it. Who knows?
In the conference call they talked about operating Sun at a significantly higher margin, and talked only about Java/Solaris/Sparc/Storage + Oracle synergy. The sum of references to open source was, "oh yeah, and Oracle still runs on Linux".
I'm a bit of a pessimist, but I'd expect to see serious downscaling of FOSS at Sun.
"Will the ownership of Solaris change Oracle’s position on Linux?
No. This transaction enhances our commitment to open standards and choice. Oracle is as committed as ever to Linux and other platforms and will continue to support and enhance our strong industry partnerships."