I would say that this is a must-watch movie both for its new message, which advocates marriage between individuals whose age differs a lot, like in this case by more than 30 years and for its light n nice humor.
Big B and Tabu (to be precise, whoever wrote the script) have done a great job by adding a great sense of humor which is hardly to be found in Bollywood movies nowadays. Big B runs an Indian restaurant in London and happens to meet Tabu somehow and the story starts there. I would not tell the whole thing here as to what happens in the end. I would advise you to watch the movie. With light comedy in the kitchen backdrop, the movie is worth the money and much more.
I don’t think the old generation would like the concept in the movie. Just imagine a situation where in your daughter is some 34 years old and some 64 year guy wants to marry her! Would you allow it?? May be after watching the movie you will say ‘I may! ‘ or considering the fact that she hasn't been able to catch any guy till now, you would probably say 'its fine!' . But I think it will be very difficult to practice, at least in the Indian sub-continent.
I would not say that it is wrong. Everybody has a right to marry whoever he/she likes. But if everybody starts doing this, human race will definitely come to an end over a period of time!! You are defying natural selection by choosing to marry somebody who is very much elder to you and who is most unlikely to help you in carrying your genes further down the stream. Am I sounding too scientific? may be! Darwin would have definitely not liked this, if he had seen this movie.
Anyways, these cases do not happen much too often in practice and we can be assured that the human race will continue to prosper.At least I will definitely try to help! I need Zyada Chini (more sugar) :)