I'd love to use something like Tarsnap, but storing my ~80GB of data with them would cost $24/month plus $0.30 per gigabyte of bandwidth. And rsync.net is $0.10 per GB of storage, so that would be $8/month. (that price only when signing up through git-annex http://www.rsync.net/products/git-annex-pricing.html )
We did our best to invite all of the backup software companies (the more the merrier)! Better deals for customers means more people backing up! To participate, drop me a line at hello@backupweek.com.
Rubbish.
A proper backup involves copies that cannot be modified after they are made (i.e. a snapshot after the backup has run if using disk, or for free on tape).
There's nothing special about an rsync/ssh solution that precludes the backup server from creating a read-only copy of each and any backup.