You can still sign up for YouTube with any email address and you'll still need to confirm whatever email address you enter. You'll also still pick a unique YouTube username that identifies you to the YouTube community.
So why are we doing this? We feel that by jointly connecting accounts, you can take greater advantage of our services both on YouTube and on Google, especially as we start to roll out new features in the future that will be powered by Google technology.
For those of you who already have a YouTube Account, don't worry, you'll still be able to enjoy YouTube with just a YouTube Account. But some of the new features we roll out down the road may require a Google Account. In these cases, we'll be there to help you link your YouTube Account to a Google Account if you want to check the features out.
Cheers,
James Phillips
Software Engineer
The YouTube Team