According to Merrill R. (Rick) Chapman's book, there is an oft repeated pattern in the computer industry where a company suddenly finds itself with two products in the same market space, and ends up not being able to sell either. They spend all their time trying to explain to customers why they should buy one or the other, when really the truth is that they are too similar to differentiate. Meanwhile a competitor (usually Microsoft) comes in with one product, a clear message ("it's the best!") and puts the other company out of business. If the other company had sold off or canceled one of its two similar products the disaster would have been avoided.
I consider that book the best book on how the major players in the software industry got to where they are today. When it came out it got hardly any press. Hardly anyone has heard of it. I think that's sad. It is a "best kept secret" book. It is written by a person that was "there when it happened" and he tells the stories in excellent detail. Each chapter teaches you something important. Oh, and most of his case studies involve companies that were beaten by Microsoft. If you don't want history to repeat itself, read this book.
If I was Oracle, I'd sell off MySQL and PostgreSQL right away.