Here is an article that explains the differences and the similarities between Lightroom and Photoshop.
In a nutshell from my own experience, I use Lightroom (LR) for my library needs, as I find the Library far superior to that found in PSE. LR is also my go to editing program for all my day-to-day editing. As LR does not have the capability to use layers, I usually go into PS/PSE for any work that I cannot do in LR.
Simone - that is an excellent article and really answers my question. Thanks for posting the link.
What really sounds good about Lightroom is how it stores the changes. I save all my psd's of all my scrapbook pages and I know how large these files can be. Good thing for me, hard drives are getting cheaper and cheaper, so this isn't a big issue anymore. Plus, for me, I need my layers. I often grab a layer from one of my scrapbook pages to use on other scrapbook pages. Having the layers available is important to me.
It seems Lightroom or ACR is not for me because fixing photos isn't my primary goal (except to make them good enough to use on a layout). Looks like I will continue using PSE.
I found using CS was even more than I needed, so went back to PSE.