I think there is value in both -- in reading through the Bible from start to finish, and in reading/studying it in depth in smaller portions.
One great value I've gleaned from reading the Bible from cover to cover, especially with the chronological plan we have here on PS, is being able to better see the whole picture of the Bible and God's overall message to us through it.
There are definite advantages to both ways of reading/studying the Bible. I'd encourage people to do both -- if not at the same time, then one year do one, and another year the other, for instance. There are also Bible reading plans out there that will take you though the Bible in several years, rather just in one, which would still give one the overall view while also allowing for more time for studying/meditating on what is read each day.
Here are a few optional plans for reading through the Bible:
http://www.bibleplan.org/