Titus,
Check my comment again. I recommended *both* against OO and against Python for the ACS. We have 1 million lines of Tcl code or so, and plenty of problems already. I do not believe that a "more extensible language" or that OO is going to solve our problems. Our problems need plain and simple software engineering work, and in that respect I like the KISS principle. Adding a new language, not matter how amazing and beautiful, will only decrease the number of potential users and increase the complexity.
I recommend you take a closer look at Tcl. It's a lot more flexible than you seem to imply, and it might be faster for you to learn more about Tcl (http://photo.net/tcl) than for you to fine tune your performance and thread-safety in Python...
