Is Unit Testing important for all?

Scott (the author of dotText - the open source bits running this blog), has an interesting <strong>question</strong> to ask, is Unit Testing important for all to include it in all the edition of Whidbey of only Visual Studio Team Systems. I think this should be a moot point. In my opinion no developer can say he/she is feature complete if they have not done a “unit test”. How can one know if their code does what it is supposed to do? Sure the QA/Test team is there, but their job is to ensure your code meets the functional requirements, but the basic building blocks only a developer knows best and it is their responsibility to ensure that they test it. Sadly, a lot of developers and designers have the attitude of “That is the QA’s job” - unfortunately they could not be further from the truth. I also find developers who do a unit test tend to have less bugs in their code (Note: this is my personal experience and recording, there is no experiment or sampling conducted). Since I am one of the advisor’s for <strong>PAG</strong> (representing the company I am employed with), I recently got the opportunity to review some of the new testing best practises they have coming out - lots of good common sense stuff - keep a look out for that in the near future. I will be posting some stuff from there here in the next few days too. Anyways, I would love to hear your viewpoint on the whole issue?