... if one hopes to find a facsimile of book review sections online, probably not. But it would take an exceptionally rigid and incurious mind to settle merely on a clone. If one wishes to discover forms of literary commentary that serve the same function as a book review section, it is extremely difficult not to find online exemplars in alternative forms.
This is precisely the point. The assumption that books are best covered by the kinds of reviews that appear in print media is false. Print reviews are generally too short these days. And as Ed notes, when more space is provided, it is often used injudiciously. The more ways a new book can be discussed and the greater the angles of approach the better. The nature of the internet is changing the nature of reviewing. Moreover, newspapers are increasingly reflective of the intellectual parochialism of those who run them.