Is Unit Testing important for all?

Scott (the author of dotText - the open source bits running this blog), has an interesting question 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 PAG (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?