In this expansion, as new content planetary interaction came and EvE-Gate came online. It was a great expansion.
In Tyrannis CCP also re-modeled the scorpion, a Caldari battleship that is also the hull for a T2 black-ops ship Widow, Long story short, it was a ugly looking ship that just got a lot better, we are expecting more of these re-modelling to be done on some of the ships. It has a great "Caldari Look" on it. :)
Overall it was a great expansion and opening up the planets is one of the first steps on moving towards the dust 514, which is a FPS for console that will bring mercenaries to New Eden for EvE players to hire to fight on planets (and perhaps even in station .... dont take my word for it :P).