This is a page for upcoming content as stated by mDiyo and other members of the TConstruct team on the official forums. However, most (if not all) of these updates have no release date.
Main Forum (Minecraft Forums): 
Suggestions Forum (Minecraft Forums): 
- Fishing poles have been confirmed to be a planned feature.
- mDiyo has stated that in a future update, Raw Aluminum will be removed completely, and all other aluminum-related items (Nugget, Ingot, Block) will be changed to Zinc. Aluminum Brass will become Brass, and Alumite will become Zarcon.
- Windmills, axles, gearboxes, and teleportation pads are confirmed as planned, and it has been hinted that they will be added to TMechworks.
- The previously mostly empty armor slots are getting stuff added. The Knapsack and original Heart Canister are obviously already used, but two new Canister slots have replaced the two slots that resembled a ring/bracelet and necklace/pendant. Gloves have also been added in the dev version, and belts and masks are confirmed as planned.