There's a nice, little summary up of some past and recent Bollywood remakes at the Hindustan Times.

Excuse me. But a cult movie is best left re-treaded. Ram Gopal Varma ki Aag put a seal on that. Doing it again is second-hand and they just can’t match the original. The solitary counterpoint to that is of course Mehboob Khan’s Aurat being turned into the classic Mother India.

Some credit may also be given to Pradeep Sarkar whose Parineeta did live up, to a degree, to the original by Bimal Roy. As for the others, frankly Farhan Akhtar’s new age Don wasn’t bad. But J P Dutta’s Umrao Jaan was. Victoria No 203 redone by Anant Mahadevan is not worth mentioning.

I tend to dislike remakes for one reason: they are usually poorly thought-out, as if the fact that a film is a remake is a chance to ignore story in favor of star quality and improved visuals. Wanting to place Aishwarya Rai in Rehka's bangles in Umrao Jaan is not a good reason to remake Umrao Jaan. If instead of retreading the material without adding anything new, why not go back to the story and find something new to emphasize? See what could appeal to a new generation and concentrate on making a new film instead of spending piles of money to make a copy of a film that was made 30 years ago - image quality deteriorates with each photocopy...

As for the upcoming remakes - well Karz is being remade as Karzzz.
( Blah, blah, Karz and Karzzz...and a couple of screencaps under here... )

Somehow, I just know they wouldn't have taken my advice, especially since Ravi and Monty are both going to be played by Himesh.