Hi guys, I'm a technet plus subscriber and as such have access to the Windows 2008 Beta programme. I'd like to write some articles about the OS on my website and include some screenshots etc... If I used these screenshots or video captures would I be breaching any of the terms and conditions?

If the software had being released to public, you should be able to write and post the print screen without concern. Microsoft had make Longhorn beta 3 available for public download. So, I don't think there will be any problem for you to write and post information related to this. What you need to take note is the information that you receive with Non-Disclosure Agreement (NDA). You should not disclose information under NDA before Microsoft make it available to the public.