Sure, but the novelty of the patent is The Random Surfer Model. That is, applying that math to the ranking of web pages. The novelty is looking at the problem from the right perspective. After you have read the paper, and seen it demonstrated to work, the "invention" is very obvious. But before that, it really isn't.
That lecture I was in described "The random waterfall model", in which you find a scientific paper, randomly pick one of the references, go to it, and continue -- and IIRC, at a small percentage, jump to a random other paper. The professor was not describing his own work, but one that was published a decade or three before.
As far as I can tell (and could tell the day I heard PageRank described a few years later), there was no difference between that and PageRank, although there is a huge practical difference in that scientific papers can only ever refer to those that were published before them (or at least were in preparation at the time), whereas web pages are edited and can point to any other web page.
The "reference rank" application is not a DAG because of the "in prepataion" links, although it is not very far - so the "jump to random paper" is much more important to produce a useful stationary distribution than in PageRank - but it is otherwise the same.
Page and Brin did a lot of interesting things, many of which weren't trivial, and were hugely rewarded for that by society. But PageRank was an application of an old idea to new medium, not a new idea - in a way that (on its face) should not deserve patent protection.
I remember Google's first days - the main selling point for the majority of people I knew was not "it finds what I want when other search engines dont" - people had learned to direct AltaVista properly more or less. The selling point was "It gives an answer in milliseconds insteads of tens of seconds". In fact, I remember complaints because it lacked the "and/or/not/near" and other features that AltaVista and Lycos already had.
