Yes, I'm sure there is a lot of code that uses string.Template, partly because I've used it in at least three different projects for three different customers ;)

If you are willing to write a patch that might get superseded by Serhiy's code (if he decides to write it :), then I say go for it.  I'm not sure what coverage is like on the Template code (not that coverage by itself is enough!)...you might want to add some more tests to make *sure* we aren't breaking backward compatibility.

But, we should see what Barry thinks :)

And yeah, that line 146 thing is probably due to the unicode coercion issues with string formatting for which there are (I believe) more than one open issue in this tracker (the most recent one was in the warnings module, I think).