I will try to answer all your questions one by one:
1. How can I check which build version Edison is currently running on?
Use the following command to check the current version running on Edison:
2. How do I understand the version numbers of the images offered for download?
The name "edison-image-ww05-15” means that it is the image version released the 5th week of the year 2015.
3. Where can I find the changelog for the current image?
You can check the Release Notes here: Intel® Edison Boards and Compute Modules — Support Package Release Notes
4. Is there a roadmap for the Edison image? Like what features are planned to be integrated and when?
There is no a roadmap like that. I'd recommend you to stay tuned at the Edison Community. You will find here announcements about Edison updates. Also, you will find all the updated documentation for Edison here: Intel Edison Support
5. Where can I find pre-release versions of the image?
You can find older versions of the software and image here: Intel® Download Center
6. Are there any images (or forks) being developed by the community?
Some users have done their own images. You can find several threads about it in the community.
7. Right now the only thing I can update is the Yocto image, no other parts like the firmware of the platform?
There is only one type of update and that is the image update. The firmware will be updated together with the image when you flash it into Edison.
I hope all your questions have been answered with this information.
I believe the information you are looking for is in the following threads:
There is a newer image that doesn't appear in the threads above. It is the WW25.5-15 (the newest) and its "configure_edison --version" output is 159.
The command does not seem to be valid anymore:
Incorrect input. Redirecting to --help
Interactive configuration options:
(none) Goes through changing the device name, password, and wifi options.
--name or -n Changes the device name
--password or -p Changes the device password
--wifi or -w Changes the wifi options
Non-interactive configuration options
--changePassword Changes the device password to the following argument
--changeName Changes the device name to the following argument
--help or -h Displays these help options
--server Starts the server (testing only)
Is there an alternative?
I actually was not able to flash the board, which is currently running the image that was pre-installed when I received it last week.
The Flash Tool is not able to find the board when I connect it but I don't know exactly why.
I managed to get a terminal session on the board and run the commands above after manually installing the FTDI drivers.
I recommend you to try flashing the Edison using the flashall script which is an alternative method. Please check the following guide where this flashing process is explained: How to Run the Flashall Script