I can't comment much on the modern academic consensus about historical materialism other than it is generally received unfavorably these days. Historical materialism was Marx's idea that history progresses through the development of material conditions, the classes in different economic formations.

I can offer, however, the answers to some popular misconceptions about historical materialism that often lead people to dismiss it out of hand.

Firstly, the idea that it is a deterministic phenomenon. Marx and Engels repeatedly warned against deterministic interpretations of their historical materialism (the example that comes to mind is in their letter to Lavrov). Marx stressed the fact that the transition to Communism wasn't inevitable, but merely that the contradictions of capitalism necessitated further development. The defining point of his philosophy was that we could impact these material conditions: "The philosophers have only interpreted the world, in various ways; the point is to change it." (His last Thesis on Feuerbach). This means that through class consciousness a worker's state could be built from the material conditions of capitalism, but not that the material conditions inevitably lead to Communism or Socialism - This eliminates the off the cuff dismissal of "Well we aren't in a Communist world, Marx was wrong".

Secondly, Marx's prediction that the most industrially advanced economy would be the first to become a worker's state. It is often referred to as a paradox that Russia was the first Socialist state, though Lenin had a ready-made correction that is neglected by imagining this as a paradox. In Lenin's Imperialism he corrects Marx's idea that industrial capital is the dominant contradiction in capitalist production, and instead places the emphasis again on finance capital. The contradictions in Russia were accelerated by foreign finance capital creating large-scale industry (compared to England where there were still smaller-scale operations that hadn't been run out of business). This created the conditions of a weakened Russian capitalist class and a more developed working class. Also critical was the broad-based peasant support (in the form of soldiers).

This obviously doesn't justify unconditional acceptance, but it does, however, dispel a few common objections to Marx's view.

"As presented in the Communist Manifesto" is a rather interesting qualifier for the question. Within that text, as presented, the Marxist view of history is often dismissed out of hand because it is asserted, but without a background of evidence to support the position.