The thing that strikes me most, and what has helped clear up some of the discomfort (?) I've had with a couple things ever since I began my own practice is the third-party influence he sees on buddhist thought. The two most notable things being his focus on how non-buddhist asceticism crept into buddhist teaching, and how liberating insight (especially as it pertains to anatta) was affected by the idea of non-buddhist liberating insight.
My first introduction to Bronkhorst was through his "Two Traditions of Meditation in Ancient India", and although his discussion of buddhist and non-buddhist meditation was very illuminating, particularly in light of the research from other authors, what stood out to me was his notion that "the explicit descriptions of the content of liberating insight are not original to Buddhism, and were added under the influence of mainstream meditation." (section 8.4). That the four noble truths, and other such fundamental tenets, as liberating insight were later additions certainly makes one pause. He discusses this idea further in other works ("Self and Meditation in Indian Buddhism", "Buddhist Teaching in India").
His insight (if you'll pardon the pun) into the doctrine of anatta is particularly elucidating. Anatta -- or rather, the way it was treated -- never really sat well with me. The concept itself is rather simple to understand. But the importance that people placed on it seemed unfounded. The idea of "self" as "process" seems self-evident, with a little bit of contemplation, but that could just be due to a background in psychology and philosophy. But I certainly wasn't -- nor am I -- liberated. Furthermore, it seemed self-evident that my own suffering/dukkha was not rooted in some illusion of a permanent, unchanging "self". Bronkhorst's explanation, explained quite well in "Self and Meditation in Indian Buddhism", removes much of the importance that mainstream theravada seems to place on anatta as liberating insight. If the idea of an "inactive self" was a non-buddhist liberating insight, it makes sense that people who didn't fully understand his teaching would latch onto his teachings about "not-self" as a similar liberating insight -- a doctrine of self defined in negative terms, with effectively the same result. It seems to me that the Buddha's teachings on anatta were not necessarily meant to be taken as any sort of liberating insight, or even necessarily a fundamental tenet of his path to liberation, but rather was a device used to get certain people to stop dwelling on the self altogether. If he was confronted by seekers who tended towards the desire to realise the "inactive self" as a method of liberation, then he would need to persuade them to stop focusing on trying to realise this elusive "inactive self" if they were to benefit from his teachings. Though Bronkhorst himself doesn't make this connection, as it's not really on his radar, it seems to be a logical bridge between the Buddha's actual teaching on anatta and what Bronkhorst sees as the final outcome of the teaching on anatta.
Whew. It's late, I'm tired, and I should probably stop here before delving into other points Bronkhorst makes.
Huifeng... your turn.
)... so feel free to weigh in with your views there, whether they be yours or Mr. Bronkhorst's.