Seeing so many releases of the Debian image in a relatively short period of time made me think. It'd be nice if there was a way to keep up to date without having to entirely reimage your SD card.
So I've thrown together a tool that lets you install the latest firmware/kernel easily. The idea is that this could be included in any distribution (since it doesn't rely on any package manager, it just needs you to have Git installed), and provide a simple way to install new firmware versions.
It's rather experimental, so it might break or do unexpected things, but I'm running it on my Pi, and I'll continue to do so, updating as each new version of the firmware is released. If you're happy to experiment, give it a go and let me know how you get on.
Currently, it updates the firmware, kernel and modules. I'm going to make it update the VC libs eventually too, once I figure out a clean way of doing so.
Instructions to install the tool are on my GitHub here: https://github.com/Hexxeh/rpi-update
Once the tool is installed, updating is as simple as typing "rpi-updater" in a root shell, or with sudo prefixed. By default, it'll use the 224MB/32MB split. If you want to use the 192MB/64MB split, then type "rpi-updater 192" instead. Same goes for 128MB splits.