I work at Oracle's Java Platform Group, where most of the managers and senior engineers came over from Sun. They all tell me that, despite the normal big-corp issues, work under Oracle's control is better than it was under Sun, where management was more chaotic, strategy unclear, and resources shifted erratically from one project to another, often wasted on unreasonable goals with bad prospects. Not only that, but the commitment to open-source has, at least so far, been stronger (although I can't speak for other parts of the company that I know little about). And because the work has yielded more success, it has resulted in more resources that are, in turn, invested more wisely in projects with better prospects.
Again, I can't speak for other parts of the company, and maybe Java's successful integration into Oracle has been a fluke (given Java's immense success and that it's at the cutting edge of compilation and runtime technology; I do know that the experience of Sun engineers in other areas has not been anything like that of the Java folks), but the Sun people in JPG have been very pleased with how it's been going overall. The work culture in the JPG and the mix of talent and personality, also compare very favourably to Google, Amazon, Apple, Microsoft, and Netflix (based on reports of friends or hires that came from those companies), and at least on three occasions engineers that left for some of these companies have come back.