A lot of my more techie (rather than fuzzy friends, using Stanford parlance) have been complaining about the Lost Finale. Lamenting that the hard-nosed sci-fi aspect was lost, in favor of less-grounded topics like mysticism.
But I believe mysticism can be grounded. I really liked Sum, a recent book written by a neuro-scientist with 40 vignettes about the afterlife, such as reliving your life with all your activities summed up (months of sleeping followed by weeks of joy, followed by months of despair, followed by days of brushing your teeth, etc.) or discovering that God is the god of amoebas, and just does not comprehend you, any more than we comprehend galaxies, or the idea that after you die, you live on in the consciousness of everyone who knows you, which makes a lot of sense, given that probably the best definition of somebody is just the information patterns in their brain, and that lives on as mental models that neuro science tells us our brains build of those around us.
Also, Stephenson's last few novels like Anathem have tried to reconcile mysticism with science, and his Baroque Cycle books which describe how Newton and Leibniz essentially invented science (and modern economics) out of alchemy and mysticism, and that reason and mysticism are actually not so different.