In India, too, where uniquely among Indian writers who have been feted in the West she continues to live, the book has been a runaway success, selling 35,000 copies in English (an averagely successful literary novel in India sells about 3,000). But in the year in which she was catapulted to fame, Ms Roy has discovered that success in the West is an ambiguous commodity at home.
Prurient fascination with her new riches, combined with a tortured attitude to foreign acclaim, have together given her a rough ride. Her fame has been overshadowed by vicious personal attacks. She has been sued for obscenity in the Kerala courts, and attacked by the venerable and powerful leader of the Communist Party of Kerala, her home state and the locale of her book. Translations of the book into India's principal vernacular languages, including Malayalam, Ms Roy's mother tongue, have been put on ice pending the resolution of the obscenity case.
As she prepares to embark on yet another triumphal tour, this time taking in Germany, Belgium, Italy, Finland and Estonia as well as Britain at Booker time, Ms Roy sits cross-legged on the floor of the two-room flat in central Delhi that she shares with her husband and two dachshunds, and ruminates on her amazing year. In her white cotton tank-top and slacks, wearing no discernible make up, she looks more like a beautiful teenage runaway than a 37-year-old literary phenomenon. But success has enforced a certain seriousness.
The obscenity suit was brought in June in the district court in Pathanam Thittla, the area next to the one where she was brought up, by a man called Sabu Thomas. The passage cited was a veiled yet sensual description of an erotic encounter that breaches caste taboo. She immediately appealed in Kerala's high court, and the judge gave a stay of 16 weeks in the criminal proceedings. "In November that runs out, and then I don't know what will happen. It was very nasty, but I don't know what to make of it. I have six or seven Indian-language publishers who are dying to get my book published, and I don't want to go ahead and do it because I can't afford 50 cases on my head. It's ridiculous, the book has been published in languages everywhere in the world, but anyone who takes it into his head to harass me can do this and I could end up spending my life going from one court to the next."
Tiresome as this is, at least it is confined within a court of law. "I'm grateful that if you're in court at least it's an argument, it's not someone saying `Get this woman'." Far more fearful are extra-legal attacks fired by religious or political sentiment: last year the nation's most famous painter, MF Hussain, had his studio wrecked and paintings burned after an old sketch of his was attacked for obscenity, and a Hindi playwright was forced publicly to kiss the feet of politicians of the chauvinistic Shiv Sena party in apology for what he had written.
So when last month Ms Roy was attacked in a weekly magazine article for her "settled ideological hostility" to Kerala's ruling Communist Party, for veering into "the realm of libel and defamation" in her reference to the party's one-time leader, EMS Namboodiripad, and of "spite, pure and simple", she had reason to be far more concerned. The attack was endorsed last week by the octogenerian Mr Namboodiripad himself, who wrote: "Arundhati Roy's defamation of me...is part of her antipathy to the Communist movement in Kerala."
"I was much more scared of that, because that's the government that is in power in Kerala and that's where my family live and that could have become really ugly," she says. "Actually I respect the Communist movement in Kerala, and I think it has done a lot of good, but if you've started a movement like that you also have to accept valid criticism, which is all I did."
India, Ms Roy remarks, is "a country that lives in several centuries simultaneously", and when mass political movements decide to mobilise against individuals or families - by calling a bandh, for example, which involves surrounding an office or home and preventing anyone from leaving - the consequences can be extremely nasty. Last year a neighbour of Ms Roy's in Kerala had an eye gouged out in such an incident. Ms Roy has not responded publicly to attacks on her, and is unwilling to comment further for fear of making things worse, but she is relieved that leftish publications in her home state have come to her defence.
Despite these anxieties, she is not planning to leave India; in fact, the attacks are one of the reasons this seasoned controversialist is pleased to stay put. "The wonderful thing about writing in this country is that it's not a clubhouse activity, you are involved in something that touches lives, it's really touching life and setting up arguments and staking your claim to territory."
The abandonment of their homeland by all India's other prominent writers puzzles and saddens her. "If it was one or two or three writers who lived outside, one wouldn't question it - what I don't understand is why in that photograph in the Indian issue of the New Yorker, 11 of the 12 writers [she was the 12th] live outside. I find it hard to understand why they don't live here. It's so much fun! It's a wonderful place to live."
Political attacks? Obscenity prosecutions? Gouged eyes? "Fun is the wrong word, but every day it makes you think, it's moral dilemma after moral dilemma. You are completely in your life and you have your finger on the pulse...When I was going down to the court in Kerala and organising my time around criminal appearances, of course it was terrible, but at the same time I know that this is the battle, and here is where I must pursue it to the end. The rest is fun and fame and all that, but I can't imagine being able to live anywhere else as a writer."