I checked my Target earlier this week and I don't think anything was on clearance, unfortunately. I did get shinebright Fluttershy and Pinkie Pie on sale, but that was over a month ago. I have all the Canterlot line except for the Canterlot Ball set (because I really don't need more doubles, especially with tinsel).
I try to check TRU, Target, and Walmart every week, and sometimes Fred Meyer too! So far the only new ponies I've seen are the wedding FS Luna and Celestia at Walmart.