Ok, so after several weeks of discontent with Mavericks + MBP + Thunderbolt Display, I think I discovered a solution (at least it works for now). Last evening, I disconnected my MBP 15" (early 2011 version) from the display to take with me to an iOS coding meetup, I dicsovered that my MBP would not go to sleep. Very troubling. So, I decided to just shut it down and took it on the road. After the upgrade to Mavericks, I guess the PRAM and SMC were pretty screwed up. When I was ready to head home from the meetup, I again tried to put the MBP to sleep. No dice. Shut it down for the trip home.
So, with that said, and when I returned home to plug my MBP back into the Thunderbolt display, I decided to take drastic measures and first reset PRAM and then the SMC before plugging the TB Display back into the computer. When I retired for the evening, I put the computer to sleep for the night.
This morning, I hit the return key and the display woke up along with the computer and it appears all is good now (let's see how long it lasts). But, for anyone else having this issue, I recommend the following steps:
1) Disconnect the display
2) Follow the instructions on resetting the PRAM and SMC on this web page http://gigaom.com/2011/07/26/when-to-reset-your-macs-pram-and-smc/
3) Once you are all done resetting the PRAM and SMC and the computer has booted normally, connect the TB Display back up.
Let me know if this works for you all, and I will update the bug I have open with Apple on this matter.