I have a mid 2011 15" MBP, 2.3 GHz i7, 16Gb RAM. This model is equipped with one thunderbolt display andport; I have 2two 27" Thunderbolt displays connected. One isdaisy chained to the other but I haveport with full resolution and no issues.
There is one item of concern however...I feel this at the edge of what my computer can handle though, my. My system resources are not taxed but my fans are on pretty high to accommodate the increased strain on my GPU...I suspect anyway.
I used @Robins link and verified my model is capable of running two displays(see item 14 in the post)...14. How many Apple Thunderbolt Displays can I use with my Mac in OS X?.