I recently discover an algorithm that solves every sudoku, i think, without T&E. (WHich is inspired by BDD-based set operation.) I planned to submit to some journal, but I now decide to post it online instead. You can access it in this way. Search for sudoku programmers forum on internet, go to the "programming sudoku" board. In the thread "Solving Every Sudoku Withoug Guessing" thread (the 2nd or the 3rd thread), click the link in the first post.
There are some discussion in that thread too, mostly I am defending that this is not bruteforcing T&E method others are using; but the algorithm need to be exhaustive in a way to be logical.