Gaming 3D Classics?

[machomuu]

Just asking... will the inclusion of 3D classics (GB/GBC) make those games/homebrew illegal? Since they are on sale again on the eShop.

those games were ALWAYS illegal if you had pirated copies of them. A copyright protects the work from the time its created until 70 years after the creators death.

Actually, since Mario, Link, etc. are owned by Nintendo inc., doesn't that mean that they are protected for 70 years after Nintendo itself goes down?

Yes. If they had not become 1st party, it would just be 70 years after Miyamoto dies, but since they are now 1st party and owned by Nintendo as well, it's after Nintendo dies.