Are you a designer mind? Do you love discussing UI / functionality related issue ? Can you think of better way to solve an issue with Windows UI / experience? Do you like suggesting things? If yes, then here is a great site that lets you discuss and 'vote' regarding windows UI issues..
http://www.istartedsomething.com/taskforce
Very nice site that I enjoy spending some time with every now and then. I love to see how different users looks at various features and what they expect.. There are also great people out there who gives really great ideas to solve complex problem in efficient way! My personal favorite on the site is 'digg' style box to cast your vote (positive or negative).. You can also leave comment to back your ideas..
Though, this is not Microsoft Official website (Microsoft should comes up with something like this to get feedback from community) but, I hope Program Managers from Microsoft will take a look at this site to 'listen to' what their users are saying (which is their primary job, I guess)!
Go, advice Microsoft to build your Dream Windows..
Stay tuned.. 