Linux Mint Debian Edition is a rolling release distro based on Debian Testing. It is currently only available in 32bit and not for other architectures.
Ubuntu to become a rolling release distro
UPDATE: Rick Spencer, Ubuntu Desktop Development Team Lead, wrote in his blog: Ubuntu is not changing to a rolling release. We are confident that our customers, partners, and the FLOSS ecosystem are well served by our current release cadence. What the article was probably referring to was the possibility of making it easier for developers [...]
