I've got an 07 LS and yesterday I was out driving when it started acting pretty funny.

I was going up a steady incline when the hand on the RPM gauge started to fluctuate pretty rapidly between 2400 and 2600 RPMs. I also noticed the car was jerking back and forth a little bit, consistent with the RPMs. All the while I had my foot steady on the gas and after about 10 or 15 seconds, it stopped.

My Mom said that there wasn't anything wrong (she was in the car with me at the time) but I'm not so sure, do you think it warrants getting it checked out by a dealer? I'll get the VIN tomorrow and maybe someone can run it and see if there have been any recalls or anything.

 

If you hit it at the right speed on a incline the tranny would start jumping back and forth between gears.(hunting for the proper gear )
The bigger cars used to be bad at around 80km\hr.
Im thinking thats what you probably experienced.

 

Probably an issue where the car couldn't make enough power with the torque converter locked. Pay attention to it for a day or so - if you don't see any other issues, I'd say the car is fine.