OMG - I feel a headache coming on just at the thought of it.
I can understand all of the reasons why people might want a name but I think there is farrrrrrrrrrrrrrrrrr to much potential for chaos - far too much.
How long is too long not to have used a name? A year? 2? 5?... I am chippingin - I'd hate to come back and find someone else using 'my' name, but on the other hand, there are some good names out there that are not being used by people who will never return to MN...??
If I were in charge of this I think I would:
Set up a system where people can request a specific name (limit of 5 per poster - it was going to be one, but in case they can't have that, I think 5 is reasonable).
MNHQ then contact the person who has the name.
No reply equals NO - it can only be 'sold' if they get permission.
50% to MN tech's bonus/50% to charity
All history attached to the name would be deleted and if there were any known problems (such as if someone choose a known troublemakers name) they would be informed as much as possible, but essentially have a 'don't come crying to us' policy.
Then - have a list of 'Names about to be auctioned' and allow everyone 2 months to object with their reason why. So if someone wanted ChippingInn or ChippinIn - I could object because it's too similar, but MNHQ would have the final say.
Right - pick that apart 
*Maybe one solution going forward would be to limit how many names we are allowed to hold onto to say 10. Anymore than that and it's one in, one out. That would free up names on a regular basis.