I myself have been working with Moodle since 2009 here at Uni SA and as such we've made a lot of interesting improvements and enhancements to our Moodle instance.
For various reasons, the code for these is stuck in 1.9 Moodle-land and as such we have a lot of work to do to bring these changes into 2.x.
To resolve this, we're planning that starting in the next couple of weeks and continuing into the new year we will port our existing Extensions module to Moodle 2.4 and, once it's close to stable, release it to the community.
It should be said that the Extensions module was intentionally specced and written to suit Uni SA, and what our Academics were asking for.
For our development efforts in porting the module this does need to be our primary focus, but given that we're intending to release this to the community we are certainly willing to hear suggestions from the community.
We'll do our best to implement suggestions that will improve the process, but there will likely be items we can't do due to time constraints.
At Moodle Moot 2012 we met a lot of people from the Tertiary sector that were as passionate as we are about moving Moodle forward, especially for our sector.
We were excited to hear the new Assign module would have extensions, however it doesn't implement as much functionality as we have now.
In this case, I'll show requesting an extension for Assignment 2, Report Internals: As you can see, there is clearly an area where a student can tell the academic that the dog ate their homework, and we've got the provision to upload supporting documentation to go along with the request (sick certificates or whatever the case may be).
Finally, they may select a date in the future (ours defaults to a short date, again this would be another configurable parameter).