It's hard to think about Star Wars without referencing one of its most beloved characters. Who hasn't wondered about the history of Yoda outside of Dagobah or the Jedi Council? I would love to see the time period in which Count Dooku served as his Padawan, or even some great exploit that told us how he came to be ranked among the top Jedis.
So why is it hard to imagine this film going well?
Personally I don't think I could handle 5 straight minutes of oddly structured sentences, let alone an entire film. I'm also not a fan of the lead role in a live action film being completely CGI. Giving too much screen time to a quirky character can dampen the likeability, and perhaps create an annoyance for a majority of film audiences (see Jar Jar Binks). Who would sell a movie like this? Who would watch such a thing? Who could possibly market a movie with all these attributes to an audience who would gladly indulge it and ask for more?!
It's times like these, when I find myself holding a torch and pitchfork amongst the doubtful geeks, that I remember they wouldn't be one of the world's largest organizations if they didn't know what they're doing. Out of all the characters in the Star Wars universe, Yoda seems most apt to be rubbing shoulders with the typical archetype that Disney looks for in it's characters. Sure, it might not turn out to be exactly what you had in mind, but when does anything Disney? They're in their element, rest assured.
There is the fact that after a long discussion, not one of our editors could come up with a successful spin off movie (Chronicles of Riddick and Jay And Silent Bob were possibly the closest choices), and you don't even want to be reminded of some of the unsuccessful...
Electra, Catwoman, Puss In Boots, Wolverine Origins, The Scorpion King... the list goes on and on. Most supporting characters don't adapt well to the lead role, and this in and of itself is a concerning issue.
So can the mentioned Yoda movie be successful? Of course it can, it wouldn't be very sporting to damn a movie right out of the gate, but history of film spin offs says no. Conversely the character Yoda itself seems a good fit for a Disney script and if anyone would have the money and talent to pull it off, it's them.