The performance improvements in this release will hopefully encourage people to upgrade, even if the new features don't. Common PHP applications run 70%-100% faster on PHP 7 than they did on PHP 5.6, comparable with or better than HHVM.
The performance increase is what I'm looking forward to most with 7. I can't wait to see how several of my code-heavy WordPress installations do with 7. From the benchmarks I've seen, it's going to be incredible.
Specifically, I'm hoping the page load times will be cut in half.
My own anecdotal evidence - I couldn't believe how fast our Drupal 7 websites were, and they only threw a couple of deprecation notices. They definitely felt 100% faster. We will be upgrading soon.
