I first noticed this in chemistry but now I'm seeing it in engineering, too. Major publishers (?), content vendors, indexes (?) are starting to offer services whereby your company can use their search tool to index your local content and display it side by side with their content OR a way to use their api to pull their content in to your local tool.
That's a common complaint in research labs and in companies. Knowledge management of internal information gets funded and defunded and is cool and then not cool... External information is familiar to people coming out of school... how can you search across both.
We have the artist formerly known as Vivissimo (now IBM something spherical I think) as an intranet search, and I would love to see it use our discovery layer type search as a tab. I don't see why it couldn't.
This deserves analysis and thought - no time. sorry!