Ricky
I don't really understand what you are talking about.
The main difference between Arduino IDE 1.X and 1.5.X is that the hard coded stuff in 1.X is brought to the boards.txt and the programmers.txt and the platform.txt.
I have already done some work on this but the Arduino core team does not share their plans and they tend to do things different from how I do things. For instance I had decided to add platform folders under hardware (like teensy does) which contains board.txt files and Arduino core team decided to have hardware/[make]/[technology]/[configuration files].
[make]=Arduino
[Technology]= avr or sam
[configuration files] = boards.txt or programmers.txt or platform.txt.
As a result I need to change my board.txt reading code. I just hate that. 
The core team noted that the whole setup may change. To avoid the frustration of doing more things twice I decided to wait untill an official release is released to see how the core team decided to do it.
rbid:
I will see if I can work on it,
Please do; the code is available at github. Fork it and go from there. GitHub - Sloeber/arduino-eclipse-plugin: A plugin to make programming the arduino in eclipse easy
rbid:
hope I'm not getting in over my head..
Why would you?
rbid:
I guess it can be done
I'm sure it can be done. I think it should even be easier now as the commands are more disclosed and the framework to do it is in-place.
rbid:
- Tailor the compiler and linker
No need to do this. The only thing that needs to be done is decide on the compiler and linker and provide them the good options.
rbid:
- Use the Arduino framework to get the same Arduino IDE look (hide all the stuff the user does not need to deal with)
If you are willing to work on a arduino IDE perspective; I'm wiling to have it as part of the IDE.
Note that the Arduino "precompiler" is needed for this to work 100%.
rbid:
- Tailor the programmer and serial console.
I really don't know what you are referring to here.
Best regards
Jantje