I went through all the picture settings, everything was where I had set them ages ago. I started to think the TV's backlight might have went out. However, I changed the input to the Roku, it wasn't dim at all... just the over the air stations.
Did a little online research, went back to the TV, and hit the "Reset" button on the "Picture Settings". Then all the stations were lit normally again. Whew!
I'm guessing the power outage changed SOMETHING in the TV, even though all the settings were where they were before the outage. Hitting "Reset" changed whatever was causing the dimness back to normal.
Hopefully it STAYS normal. I really don't feel like going TV shopping.