68tjs:
Use IDE Arduino with latest avr-gcc-4.7.2 is easy :
- don't use Arduino IDE from Arduino
- use Debian Linux and IDE only from debian package repositery.
If Debian knows how to use the latest version of avr-gcc, it is the proof that this is possible.
If Debian did it, Arduino team should be able to do so. If necessary they can copy on Debian.
Same for Slackware (Third party packages, though).
Problems with that are:
1: Windows 
(People using this are usually the least technical)
2: macos
3: Getting the Arduino devs to not drag their feet, and either get on it, or hire someone to do it.
Really, they aught not release any more new over-hyped hardware 'till the tools are better.