" Debian, for instance, seem to have something of a lowest-common-denominator approach that targets features present everywhere."
Debian actually has three ARM ports in progress.
ArmEabiPort - newer port using the "new" ABI (EABI), supported on ARM v4t and higher. First released with 5.0 (Lenny). GNU Triplet: arm-linux-gnueabi
ArmHardFloatPort - the latest 32-bit port, using the hard-float version of the "new" ABI (EABI), targetting ARM v7 and up. To be released with 7.0 (Wheezy). GNU Triplet: arm-linux-gnueabihf
Arm64Port - the latest port, for the 64-bit ARMv8 architecture. Likely to be released with 8.0 (Jessie). GNU Triplet: aarch64-linux-gnu
Debian actually has three ARM ports in progress.
ArmEabiPort - newer port using the "new" ABI (EABI), supported on ARM v4t and higher. First released with 5.0 (Lenny). GNU Triplet: arm-linux-gnueabi
ArmHardFloatPort - the latest 32-bit port, using the hard-float version of the "new" ABI (EABI), targetting ARM v7 and up. To be released with 7.0 (Wheezy). GNU Triplet: arm-linux-gnueabihf
Arm64Port - the latest port, for the 64-bit ARMv8 architecture. Likely to be released with 8.0 (Jessie). GNU Triplet: aarch64-linux-gnu
http://wiki.debian.org/ArmPorts