Which company's future looks more dim? Nintendo or Sony?

[Cj2i3]

Neither both companies future's will be bright.

For Sony they are going through a new transition, since Kaz Hirai stepped up as CEO in 2012 they have made some drastic much needed changes. Obviously Sony is restructuring it's business model acknowledging that their expensive high-quality products aren't in demand. People want the BEST PRODUCTS for the CHEAPEST PRICE.
For now Sony will stick to what it's good at; Entertainment(Music/Movies), and Hardware(Playstation) etc...
Restructuring takes more than a few years, it will take Sony another 2 perhaps 3 years to get back on track.

Nintendo is in decent shape, they were really relying on the Wii U to be Wii popular. Unfortunately that wasn't the case.
3DS profit will offset the Wii U losses, and vice versa. They know their target demographic better than anyone else (ages 5+), but gimmicky controls will have to stop or they will have to come up with something very bold(aka a new way to play) to get a leg up on Microsoft and Sony as far as consoles go.

Overall both futures are bright look for Nintendo to get back on track in about 6 months to 18 months.