It makes sense that Oracle would buy Siebel. Their products play together nicely, and that simple fact–rather, that we know that simple fact–indicates they have many of the same customers. This isn’t a shocker.
The better question is, Does Oracle have anything new of its own to offer?
Let me hypothesize that transactional databases are a mature technology. You can make them better by optimizing what they already do, but the new ideas involve databases to be read, searched, and repurposed rather than written.
What, then, does Oracle have to offer?
Why, yes, I’ve worked for the last several with very large data warehouses–what on earth makes you ask that?