As noted, customers can usually request hotfixes for issues via their support contact or by placing a call in to Customer Support. Now, you can request hotfixes associated with a particular KB article via a simple web application that allows you to submit a request and receive the hotfix via email.
A Hotfix is a single package that includes one or more files that is used to address a very specific customer problem with a product. A supported Hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in the previous mentioned article. Only apply it to systems that are experiencing this specific problem. This Hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this Hotfix.
To obtain this Hotfix, please submit your request via this form to Microsoft Online Customer Service and Support – you should expect to receive a download link via email from Microsoft within 8 business hours.
You can get more details on Todd's blog at http://blogs.msdn.com/toddca/archive/2007/07/27/download-your-hotfixes.aspx.
As noted on the request page, "hotfixes have not gone through full Microsoft regression testing, so please carefully review the associated KB article for each Hotfix you install to verify that this is the fix you need and that there are no known compatibility or installation issues."