Maybe I'm just going nuts then! I could have sworn that whenever I closed, then opened the smart cover, my iPad would go back to the lock screen (just like when you hit the power button to lock your iPad) and I'd have to use the slide to unlock button to get back to the home screen. I don't have a passcode set, so I'd just get the "slide to unlock" slider at the bottom of the screen.
For example, If I'm using the Mail app and close the smart cover.....I'm still in the Mail app when I open the cover again. This behavior holds true for any app....not just Mail.
This is NOT a big deal and if I really want to lock my iPad, I'll set a passcode. I was just curious because I thought for sure that after opening the smart cover, I used to be sent to the lock screen.
Thanks for both responses!