For those who have asked about an opt-out option, it's not going to be possible for us to provide that for the profile page or any other significant UI changes. While we would like to be able to support every permutation of the product, adding more complexity at core levels makes it really difficult to design and maintain.
For users that have been with LiveJournal for a long time, it may be hard to understand why we continue to evolve the user interface design. There are a number of factors that go into our decision making process when we make changes to the design of LiveJournal. User feedback is one of the most important ones, but it's not the only factor. Our goal with the profile page redesign and all the user interface design work is simply to make the website easier for everyone to use, which includes new users.
We know that for you, this may seem not very useful, since you already understand how to use the product. This is why we go through the painstaking process of creating beta versions, getting feedback, creating a new beta version and so on and so on until we achieve something that we feel comfortable launching. It's impossible for us to satisfy everyone, but we still try.
The profile page is a very difficult page to design given the personal nature of the information that is on there. The Account Settings project I think is a more clear cut example of how we are improving the LiveJournal experience for both new and old users alike.