I've been slowly gathering supplies for my DS6 to create an invention box. I have a large plastic bin that I am filling with many types of fabric remnants, chip bag clips (he uses clips and fabric to make costumes for plays and it's become quite open ended), plastic tubes, containers, shiny rocks, thrift store objects, washers, bolts... You get the idea. I think he's going to freak out! And, at least I have some way to contain the invention parts that end up all over our house!
Also, Raspberri Pi kit, solar radio with hand crank, magic kit and quite a few books. I'm sure he'll get some Lego and science kits from relatives.

He still plays weekly with the Thames and Kosmos Solar kit he got this summer.