Blessed

[Douglas G. Wilson]

 >Blessed as a verb is /blEst/
 >Blessed as an adjective is /blEs ed/

I think the adjective is either way.

 >Are there other examples of this process?

The most obvious one is "cursed".

 >Can anyone comment on the adjective pronunciation? Is it an emphatic
usage started in the church (Blessed Virgin) that has become accepted?

I can comment on anything, but not necessarily sensibly or cogently. I
think the stretched versions of "blessed" and "cursed" are probably favored
by solemn/pompous/weighty church or church-like uses. There are also poetic
uses ("the hornéd moon") and jocular ones ("I'm not [stupid/stoopéd], I'm
standing up straight").

-- Doug Wilson