Vir Sanghvi writes about "Punjabi-isation of India". He's partly right, but generally wrong. His premisses that Hindi cinema is influencing pop culture in a significant way, and that Hindi cinema by and large depicts Punjabi stereotypes, are valid. But his conclusion that India has become "Punjabi-ised" (as a result), does not hold. Naturally, there's nothing right or wrong about the said Punjabi (or any other) melting pot, (though I do have my personal views about such a thing). Except that it does not exist.
Interim Thoughts has a good post on this which makes some of the points I had in mind. For example, the pervasiveness of Idli and Uddina Vade. Further, although it's true that Punjabi food has made a major impact in big cities in the South, more in dinner than in lunch, Andhra meals is also quite formidable. Even if we give it to Punjabi food, it is not clear to me how much it has got to do with movies or TV. I would imagine drinking espresso based coffees or eating pizza to be more direct effects of movies or TV.
The prevalence of Punjabi food in tourist locations in Kerala or anywhere else can be explained without the so called Punjabi-isation. It is not significantly different from the non-usage of coconut oil for cooking in those places.
Hindi movies are terribly popular, but that's not all. It's amazing how popular Telugu movies are in a place like Dharwad. Telugu movies run for 100s of days regularly. Even in Belgaum, the bigger Telugu hits run for a long time!
Karva chauth or whatever it is called might be the most brilliant motif in Hindi cinema since "duniya ki koyi bhi taaqat use nahi bacha sakta", but unlike Sanghvi, I am not sure if women everywhere have started observing it suddenly. Moreover, I know of at least one ritual -- Bheemana amavaasye -- which is quite similar to Karva chauth, observed in Karnataka. Similar rituals might exist elsewhere. With respect to other festivals also, I don't think there's any significant change due either to Punjabi culture and/or movies. Probably indoor rituals and customs have reduced a bit, and outdoor activities have increased, due to the changing times.
Salwar kameez is probably the most popular dress, but saris do return during ceremonies. On the other hand, trousers stay.
All that aside, one of the more direct influences of Hindi movies that I have seen in (some parts of) the South is the taking in of Hindi words for relationships. The increasing usage of funny words such as "bhabhi", "devar", "jeeju" etc. in lieu of age old local equivalents is definitely a direct effect of Hindi movies. However, this is more likely a 'Barajatya effect' than a 'Johar-Chopra' Punjabi effect. This is significant because this has extended beyond big cities, and it has invaded households. This is unlike most other effects which can be seen mostly in big cities and outside of the family. You can find young men and women in a place like Gokak inserting these terms quite naturally in their otherwise unadulterated Kannada.
The point is that memes are running along in all directions. Even the trivial, and pretty annoying ones like the Kannada verb maaDi, (ex: enjoy maaDi, relax maaDi), being used by Hindi speaking folks all over Bangalore.
While it is quite annoying to see the Raj Malhotras and the Rahul Singhanias of the world singing, dancing, oye-hoying and generally making merry all the time, I am sure there is much more to Punjabi pop culture than that, let alone Indian pop culture.