With Kernel 3.8 and later, it's no longer necessary to resize the root partition in cloud images in the initrd while root is unmounted, it can now be done online during the regular sysv boot process. That makes cloud-initramsfs-tools kind of obsolete (for newer kernels that is).
Secondly, growpart (which is part of cloud-utils) kind of grew into the wild IMHO. I'd like to start over from scratch.
Thirdly, apparently the ARM people are using the growroot feature so they can put their image on any-sized SD card and it enlarges itself on first boot. That's not really a cloud use case so having to install cloud packages (which pull in other cloud dependencies) for that is suboptimal.
What I'm proposing is to create a new package that does both partition and filesystem resizing during sysv boot. Just that, nothing else, probably configurable somehow through a config file. In functionality, it would replace cloud-utils (more precisely, the growpart script) and cloud-initramfs-tools and could probably replace the two over time.
I'm not a DD or package maintainer so don't really now how to go about it. I could put something together and throw it up on github as a starter.