The coolest ones are the ones they plan to send to the Moon to build things there. Because they can use a range of tools to build things made up of components, they are capable of reproducing themselves. As long as there is always one working system, the others can be repaired by it and as long as we continue to send them materials, they can continue apace. They are also programmed to automatically disassemble other systems in order to free up materials necessary to perform other more crucial tasks, so they do not require human commands to function - which would be essential in the event that communications were lost.

These things are ready now, they just need to be fully tested and then deployed, but once they are out there they will be able to effectively colonise the Moon.

Scary or exciting?