With most flat design sites I have the feeling I've seen them before. With the new Virgin site I don't have this feeling. Although it didn't work for you haha.
Most flat design websites currently all use the same flat colors and the Flat UI template.
Flat design websites that are created by excellent designers begin to use gradients with specific color combinations. Like Stripe.
There's also an ongoing trend by using more thin fonts and thin graphs in charts. Looks more elegant. I really like this, but UX wise I hear a lot of signals that people find it hard to read.
Huh - did we look at the same site? Just the same old minimal bootstrap3core aesthetic that's everywhere nowadays. Found it pleasant to use, though.