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.
|Black on White by RaVN11|
|Hummingbird and Bee by dibilio57|
from A Big Year - birds
|xheneta iseni _for DPReview by Mike Slade|
from - My Fair Lady - (Portraits in Full Colours Only + A Border)