You'll have to wait just a little bit longer to play the expansion

According to EVE Online's website, EVE Online: Tyrannis' deployment was supposed to be today at 18:00 UTC, but EVE's quality assurance team has delayed the deployment of the new content. A new update about when players can experience Tyrannis will be available at 18:00 UTC. I guess getting planets ready to be mined by EVE's voracious community is a big job.