Microsoft would only be able to make like 10 of their toys-to-life characters.
Yeah, they've got Halo, Minecraft, GOW and Rare IPs. Not a whole lot else. Fable is basically dead, and Twisted Pixel haven't made much for years now.
I can't see them being able to get into an already over crowded market without more huge IPs, not when they're competing with Skylanders which was the 1st, so it has a big built-in fanbase.
Disney which also has use of Pixar, Marvel, Spiderman, Muppets and Indiana Jones (as well as LOST if they ever wanted to use it).
Nintendo, who has a huge array of popular 1st Party IPs and a big foundation of products to use them in.
They'd probably have a better chance of doing it than Sony though.