Looks like Google Base replaced Froogle Merchant center this morning. Uploads to hedwig no longer work, instead one has to upload the file to uploads.google.com. From the FAQ, it seems that they will accept the old Froogle product feeds without change. However, to conform to the Google bulk upload specs, the fields names in the header line have to be changed. As of right now, trying to log into the Google Base website is giving a 403 Forbidden error. However, uploads.google.com does seem to be accepting uploads by FTP.
It also looks like Google Base will have an interface where you can add/edit your products directly online. A lot of Froogle feeder tools may become useless.