Late last week I got my invite to the developer beta for Google Storage. This is going to be good competition for Amazon S3 and I've kicked off some code for the Perl bindings which you can spot on Github and fork away as you please. Its pretty basic but does actually get lists of buckets. Right now I'm working on tests to ensure the way I am signing the https headers is correct since that seems to be the bulk of the code work.
Basically I intend to just copy Amazon::S3 for now so that we can make it easier for people to switch between them. As I come to understand the API better I may deviate if/when it makes sense. I guess at some point we can just do a "AnyCloudStorage" to wrap all these up.