Picasa and Sony A550
The last time they added any new cameras to the supported list for RAW files was in November 2009 from what I can see from the change log:
Some of the newer Sony models made it in that update (A230, A330, A380, A850) but not the A500 or A550 (neither work in the latest 3.6 update for it).
I've got RAW files from the A700, A850, A550 and A500 on my PC, and the latest update from Picasa does not yet decode .arw files from A500 or A550.
|Bianca Buitendag-7809 by vbuhay|
|Sunrise in Paradise by OB Foto|
from Booby Prize
|The Battle for the Lead by Photo Pete|
from Bicycle sports
|Cecelia's Eyes by Madeleine Hart|
from - Jenny from the Block - (Colors that pop + A white Border)