Safe Software will write a reader, a writer and some others functionalities to interact with rasters stored in PostGIS! These tools should be released with FME 2013 and already available in future beta versions of FME this fall. A great news for the PostGIS community!
On the GDAL side, thanks to Jorge Arevalo, lots of improvements have been recently done on the PostGIS Raster driver. You can now read irregular arrangements of raster and translate them into any format supported by GDAL. We are still looking for sponsors to implement the writer part of the driver.