Hi osm101,
To provide any type off feedback ( as all feedback is valued) Just Bing onto the Microsoft Support site, (make sure you are signed in) Scroll down to the bottom of the page and you will see the "Contact Us" option. Please then expand the "Microsoft customer
support- help for general enquiries", option and select the "Product sales and licensing section". There you will see the "E-mail Us" field, please select this and complete all area's. Or just click-
http://support.microsoft.com/gp/cu_sc_prodinfo_master/en-gb
I take it you wish to give feedback regarding Windows 8, While suggestions are still being taken on board the best time for this was during the Beta versions when all feedback was more or less on a live response.
Also, when if you locate the page similar to the topic/subject that you are using on
http://windows.microsoft.com/en-GB/windows/home by using any of the "Was This Helpful" is a great way for feedback.
Once you find an area subject within the Microsoft family and sign up to the news boards and relevant communities, you will know and here all about the new products that needs testers to use and provide feedback, as it sounds like this is something you have
a great interest in, this would be a great option for you!
Also, please do not ignore the features of the Microsoft Community as within all the Communities is were the biggest options to gain assistance and provide feedback regarding all products are. Share and post!
After all, it was here in this same area (That you posted your question) that some of the testing and feedback was and has been taking place for Windows 8 (amongst others).
Microsoft is a very large and complex family and as such can not just give one support address like Apple can.(Could you imagine the nightmare of sorting and locating valuable feedback, so much would get lost or go un-noticed.) This is why Microsoft prefer
to get you the right address and not just a common one. All you have to do is decide what product you are testing/using/building or developing. Then just locate the community to join from here- http://answers.microsoft.com/en-us/Page/forums
Or just use one of the other options I have already listed above in my other posting, there are countless ways to get in touch and if it is that urgent then just call.
Hope this helps!