Hello Jon
Blueberries do differ from most other ericaious plants in that they
only favourablly grow at low pH levels. There are a few (Southern
High bush cultivars such as Sunshine Blue) that tollerate conditions
closer to neutral - but do better in acidic conditions.
Chris has outlined the botany, except that Sequestrine type products
don't seem to revive them - it is almost a question of once the damage
is done, its done - in my experience.
I have not seen Blueberries grow in bog conditions. Cranberries are
closer, but not wet.

below is a copy of text taken from the Dorset Blueberry company's site

"Blueberries and other vaccinnium plants can be successfully grown in
the open garden, containers or raised beds where soil suitable for
other ericaceous plants such as Rhododendrons, Azaleas and Heathers
can be provided.

Optimum soil acidity should be between pH 4.5 and 5.5, however they
will tolerate soil around pH6 where plenty of organic matter such as
fine pine chippings or peat has been incorporated.

Blueberries will provide the best flavoured fruit and the brightest
autumn colour when positioned in full sun.

They are tolerant of wind, but in extremely exposed conditions some
shelter is advantageous. Cold conditions down to -12C for short
periods are acceptable for most varieties. The root systems of
container grown plants, however, benefit from some form of protection
in winter, such as fleece, straw or hessian sacking."

The Trehane family who run the company have many years experience of
commercial production of Camaelias and now Blueberries. Experience up
here in the North has lead us to add sharp sand / top soil to the mix
otherwise they seem to rot the roots