GoNintendo is really sticking their neck out with this rumor. Supposedly, they received a copy of a corporate PowerPoint presentation in which Cisco provided information for Hasbro on their competitors and what they were up to. Basically it's a presentation that gives Hasbro an idea of what they're competitors will be doing and how best to react to it in the forthcoming year. Things get SUPER interesting when it comes to this part...
In a 'competitor update' slide, there's mention of some projects that Mattel and Disney is taking on. Mattel had some shifting of executives, which is mentioned in small detail. A few points about Disney are mentioned, but the one in particular we're interested in states that 'Nintendo and Disney are coming together to create movies'. There are no other details provided, but I think that one mention is certainly interesting enough.
Obviously this is a damned if you do, damned if you don't situation. Even if this is 100% true, you're not going to get a confirmation from Disney or Nintendo. The two are both corporate clap traps when it comes to leaks. I would be curious to see the PowerPoint for myself, as it would be really easy for some Joe schmoe to obtain an official PowerPoint, spike some information in there, and then send it to the press.
Still, the fan in me really wants to believe Disney is working towards making a great Nintendo movie that isn't Wreck It Ralph 2! I would love for a well done Mario movie! Mind you this is still very much a rumor, and until we hear otherwise we confirm nothing!