I had looked at TunerPro (http://tunerpro.markmansur.com/) in the past and thought it would be a cool option for us to have available. I made contact with Mark, the developer, and he started working with the info I was able to gather from Spiider's posts.
As of now, he has made a few changes to his core software so it will work for us, and we have a working 2004 USDM WRX definition file. This file seems to work for 2004-2005 USDM WRX so far.
I have been, and will continue to keep mark updated on our progress over here, and he has promised to support our needs to the best of his ability. He has already invested a considerable amount of time on the things I have requested.
Currently, Mark is converting the defintions from little to big endian, but the software is working fine at the moment, and the current definition file has most of the important maps.
You can download the software here:
http://tunerpro.markmansur.com/
Click to the downloads section and the link will be right at the top.
The software is 100% free for all versions, though Mark does ask for a donation for the RT version if you want to eliminate the delay screen.
Feel free to post suggestions here, I am sure he would love to see what we think.
BTW, the tables will display the rows from High to Low.
This will be changeable in the next version (5.0)
Big Ass Screenshot: