Open Stack

I am pretty close to fully implementing the api defined in this 
blueprint, here:

https://blueprints.launchpad.net/nova/+spec/public-and-private-dns

Alas, I'm also about to attend a meeting at which Wikimedia folks will 
almost certainly agree that we need a few features added to that api in 
order to get what we need.

I doubt that anyone but me is keeping much of an eye on this extension, 
but it nonetheless feels rude for me to unilaterally modify it when it 
is already a part of a release schedule.  Is there an established 
process for modifying existing designs?  Should I just go ahead and 
modify the blueprint, or write a new 'extend-the-extension' blueprint?  
Or something else?

Thanks!

- Andrew