As a reminder, Picasa is a software (literally) offered by Google which allows to crop and retouch one’s pictures in a fairly easy way. Of course, this does not come up to a software like Photoshop, but it offers first-level retouching. Besides, Picasa Web Album allows to easily publish on the web the pictures that one has on a hard disk and that are locally handled via Picasa.
However, up to now Google apparently has not found it interesting to make this service Mac-compatible. If we are to believe what Apple Insider announces, this should change now with beta versions which would have been provided to happy testers. It is strange sometimes to see the gap between Google’s willingness to provide iPhone apps such as StreetView or Vocal, and their lack of reactivity in making Mac-compatible such essential applications as Picasa.