You'd probably do well to check out Fiefs and Vassals by Susan Reynolds. It's pretty much essential reading if you want to know the other side of the debate with Bloch's view that's been rumbling on since Elizabeth Brown's article The Tyranny of a Construct.

Unfortunately, most of the recent literature (excluding Susan Reynolds' Fiefs and Vassals, an important reflection on the concepts in play) is written in French. The first heir of Bloch in the domain was Georges Duby, who theorised a model of sudden change in the years 970 - 1030, based on his research on the Mâconnais, a sub-region of Burgundy. Then, in the 80s, Dominique Barthélémy, one of his students, reversed the paradigms, and tried to show that the apparent sudden development of feudalism was in fact due to a change in vocabulary, but that the essential structures had been existing for quite a while (for this reason, he approves of Reynolds' reflection, though he thinks that she is sometimes throwing the baby out with the bath water). This article, though it is basically a pro domo plea by Barthélémy, does give an idea of the debate, and of the main historians involved in what has been called the “mutationnist” debate (but the best summary is probably this article by Christian Lauranson-Rosaz, if you can read French).

I notice that Barthélémy has recently (2009) published a book in English, The Serf, the Knight, and the Historian. I do not know what it is worth, but I assume it will essentially be a summary/recapitulation of his theses. For an example of the books that which Barthélémy began to criticise, you can have a look at Guy Bois' monography on the village of Lournand, The Transformation of the Year One Thousand. There are still modern proponents of a sudden change, like Jean-Pierre Poly and Pierre Bonnassie, who generally tend to focus on southern Francia (esp. Catalonia). However, Barthélémy's books usually tend to feature important discussions of historiography, and in spite of his tendency to like controversy, he generally addresses the books of his “opponents” in a reasonably fair way — so I guess that you will get a good idea of the opinions of each side by reading his book.