For a year or so now, Fairpoint has been providing DSL to
some houses near the town center, particularly along South
Road. My place, at 1702 South Rd, is one of those.

I'm not aware of any specific future plans for DSL coverage.
Fairpoint declared bankruptcy last October ... which can't
be a good sign. (See for example
http://www.nytimes.com/2009/10/27/technology/companies/27fairpoint.html .)

I believe that Patrick Moreland has had some conversations
with Fairpoint. He might have more information. But
"throughout Marlboro" sounds very unlikely to me.

"It has been said" isn't very informative. Can you
be more specific?