The Internet is ever-changing, and YouTube is no exception. With Google's switch to a more minimal homepage design, it comes as no surprise that YouTube will be following that path as well. The changes aren't too dramatic, but they seem to help streamline user interaction with each video page. So instead of waiting for the newest YouTube remodel, why not take a look at it now? Here's how to get started:
Note: The following instructions have only been tested for Chrome, Firefox, Opera, and Internet Explorer.

Step 1: Open your browser of choice and open any video on YouTube.
Step 2: Gain access to the browser's console by doing the following:
Chrome: press Shift+Ctrl+J
Firefox: press Shift+Ctrl+K
Opera: press Shift+Ctrl+i and select Console in the pane that opens
Internet Explorer: press F12 and select Console in the pane that opens
Step 3: Copy and paste the following text into your browser's console:
document.cookie="VISITOR_INFO1_LIVE=CuSA6Z9VUog;path=/; domain=.youtube.com";window.location.reload();
and then hit enter.
Step 4: Regardless of what the console says and what the page does following this, reload the YouTube page by either hitting the refresh button or pressing the F5 key.
If the previous steps were done correctly, you should notice some aesthetic changes to your YouTube page!
(optional) Step 5: If you wish to revert to the old viewing method, simply delete your cookies. The location to perform this option is browser-specific and listed below:
Chrome: Settings menu -> Tools -> Clear browsing data...
Firefox: Firefox menu -> History -> Clear Recent History...
Opera: Opera menu -> Settings -> Delete Private Data...
Internet Explorer: Tools menu -> Internet options. Find the Browsing history heading in the General tab and click the Delete... button.
Keep in mind that clearing your browser data may also reset saved passwords. Most of the prompts that appear when you attempt to clear the data will have check boxes that allow you to specify exactly what data to delete. If your saved passwords are very precious to you, simply uncheck the box next to the option to keep them intact. That being said, there's little to no risk in previewing this YouTube interface change. If you are using any browser plug-ins that interact with YouTube videos the change will most likely cause them to lose functionality, but there is no real reason to change back to the default view otherwise.
(Via gHacks)