Trying to figure out what you are allowed to build can be difficult at times, especially as you advance into more complicated items (Titan ships, Plasma Turrets, etc.) The new Technology Tree view helps alleviate the pain by showing you every technology, ship, defense, industry, and ground troop you can build in the game. Not only can you see each item but you also can see everything required to build it with connections to the required objects.
In the prototype screenshot you see the Large Cargo ship that requires the Space Port industry and Combustion technology to build. The Space Port industry links to the master Space Port object so you can see what is required to build it. The Combustion technology links to the master Combustion Technology as well.
In addition to the links, you see a green check-mark for those items you meet the requirements for. For items where you do not meet the requirements, you see a red x-mark. In addition to the red x-mark you also see the number of levels needed to make it green (and available.) In the same screenshot you can see that the Large Cargo ship requires one more level in Combustion technology before that requirement is met.
This view makes it quick and easy to see what is needed to build a particular item and the various buttons will allow you to "warp "to the scene needed (the Manage Planet scene or the Research scenes respectively) with the item you need pre-selected for you. Overall this should be a pretty exciting addition for veterans and new players alike!
