I would argue that the best travel books do not even come under the travel label: they may thought of as books of history, anthropology or politics. In fact, my favorite books this year -- Pankaj Mishra's Butter Chicken in Ludhiana; Basharat Peer's Curfewed Night; Ahmed Rashid's Descent Into Chaos; Vaasanthi's Cut-outs, Caste and Cine Stars; Sumantra Bose's Contested Lands; Hooman Majd's The Ayatollah Begs to Differ -- are all travel books, even though their authors may not think of them in such a narrow way.
The question remains: does travel writing have a future? The tales of Marco Polo, or the explorations of "Bokhara Burnes" may have contained valuable empirical information impossible to harvest elsewhere, but is there really any point to the genre in the age of the internet, when you can instantly gather reliable knowledge about anywhere in the globe?
Certainly, the sort of attitudes to "abroad" that characterised the writers of the 1930s, and which had a strange afterlife in the curmudgeonly prose of Theroux and his imitators, now appears dated and racist. Indeed, the globalised world has now become so complex that notions of national character and particularity - the essence of so many 20th-century travelogues - is becoming increasingly untenable, and even distasteful. So has the concept of the western observer coolly assessing eastern cultures with the detachment of a Victorian butterfly collector, dispassionately pinning his captives to the pages of his album. In an age when east to west migrations are so much more common than those from west to east, the "funny foreigners" who were once regarded as such amusing material by travel writers are now writing some of the best travel pieces themselves. Even just to take a few of those with roots in India - Vidia Naipaul, Pico Iyer, Amitav Ghosh, Vikram Seth and Pankaj Mishra - is to list many of the most highly regarded writers currently at work.
So Dalrymple's question, whether travel writing has a future, is a bit silly -- just small talk. Good nonfiction writing about a place or people -- whether it is history, a particular sociopolitical trend, or current affairs -- automatically qualifies as travel writing. And there's plenty of it going around.