Robo Supposed to be Shankar's dream project, expensive, sci-fi film that would take Tamil cinema to the next level. I think the first time I heard about the movie was before Anniyan, as Shankar was looking for a project that would erase memories of the Boys debacle.
Now the big question here is , who is the hero of this project? I think the project was first supposed to star Kamal but then Vikram's name was suggested. The project then moved to Bollywood since it was supposed to be so expensive that it needed a national - rather than a regional - hero to have any chance of making money. Hrithik Roshan was mentioned first but after that, the project seemed finalized as Shah Rukh Khan signed for a dual role - acting and producing. He even talked about it as an upcoming project in one of his pre-Chak De India! interviews. But then it was unceremoniously dropped with the reason being the ever-popular, vague "creative differences". After a few reports about Aamir Khan being approached, news about the film moved south again as the next rumor had Ajith teaming up with Shankar for the film.
Suddenly Shankar has signed on Rajnikanth for Robot. The news item talks about a Mumbai production house backing the film, which would have a higher budget than even Sivaji and would be the most expensive Indian film ever.The story is about "a scientist who creates a robot and later runs into trouble with his pet creation") which doesn't seem like Rajni material at all. Considering Sivaji's success, any film with Shankar and Rajni would likely have mega-expectations and mega-money on it and I don't think either of them will take risk by casting Rajni in a non-traditional role. Rajni himself was supposed to considering scripts from K.S.Ravikumar and Murugadoss for his next film and his doing back-to-back films with Shankar wasn't mentioned at all.None of the other websites have anything on this yet.
So for now, all we can do is wait and watch...