Tyrannis will become one of two things in time. It will either an interwoven essential layer of EVE that demands attention, or it will become a non-essential extension that a niche amount of players will partake in with nominal consequence.
That said, I really hope the former is the case as it offers the opportunity to provide economic PvP far more comprehensive and interesting than staring at the market/contract windows with a few billion isk in your wallet. This is because it will allow some aspects of empire manufacturing to be vulnerable, so no longer will you compete to sell your 'stuff' you will now have to compete to make 'stuff'. Now, this is of little consequence if said 'stuff' is either of little value or available through alternate means, which will take time to transition to.
Assuming that Planetary Interaction does become important I see great potential for the concept of planetary sovereignty. One idea is to allow material/product transport between different sectors of the planet, whether to others you own or, if you both have the setting allowed, to corporation members. This would allow different sectors to serve different purposes, and thus less homogeneous. I imagine having one heavily militarized sector where the products from all my corpmates' production sectors are stored and gathered, allowing simplified jettisoning and storage. This would of course come with disadvantages as the inter-sector routes could be disrupted(opportunity for conflict), and that the "port" sector would be a big target.
Another idea is that between sectors, you could transfer human capital; transferring citizens, slaves, or soldiers(for use when dust is implemented and you do not wish to contract out your defense). This allows for yet another variety sector, one in which you allows you to provide a utopia for population growth until you decide to move them to somewhere else on the planet less favorable(where populations may be prone to declining).
Just a few of my ideas, if I keep going I'm sure I could write a few more pages, but it is hard to do so without knowing what is in-store for sure. I hope my ideas are practical enough to the current design as it would offer more depth I believe.