Eric,
I'm not sure why you seem to belittle Photoshop so much when comparing it to Lightroom. It is so much more powerful, also for the photographer.
The raw editing capabilities of Photoshop (Adobe Camera Raw, ACR) are exactly those of Lightroom, albeit with a different interface. Where Lightroom stops at raw editing, Photoshop continues, offering a host of tools and capabilities.
Sure, >90% of your editing needs can usually be met with the capabilities of ACR/Lightroom, but for the rest you will always need something like Photoshop (or Aperture for that matter). Not only for combining multiple images like for HDR and Panos, but also for the more advanced image editing/retouching.
Contrary to your statement, I would therefore actually say that >>90% of the professionals use Photoshop as (primary) tool. Perhaps in combination with Lightroom as catalogue/browser (and raw editor), but still, the primary need would be PS, not LR (PhotoMechanic or even Bridge can fulfil many needs in the browsing/cataloging area).