You are going to create a new fork
You can just abuse standard DNS for this... just stick a TXT record in a well known place eg. _bitcoin,
Namecoin is not a domain name system, but a name→value associated array. So there isn't a need for a hack or fork. That's the beauty of the whole idea!
A Namecoin "name" is composed of slash-seperated substrings, first of which is the "application specifier".
The current domain name system based on Namecoin uses the "d/" application specifier, with "s/" OR "dd/" proposed to specify extra domain data. That is, if you register "d/example", the value will contain information for example.bit
However the chain will be used for other applications, such as keys, personal contact information, etc. and we need a standard specification so that we can link these together (link keys to domains or contact info for instance).
Bitcoin URI's come up as a good addition to a generic "contact info" entry. So, you will only need one name to store, for instance, your company address, skype id and bitcoin address, and applications can extract the info they need automatically.
So basically, when I say "send bitcoin to StoreX", the program will go and fetch the "p/StoreX" entry (or "c/StoreX" or whatever the standard scheme is) from Namecoin and get StoreX's bitcoin address from that.
Standard can be defined so that Namecoin values can import data from other names, which will allow distributing this data and delegating parts of it to other parties. Namecoin is a generic datastore with the same authoritative structure as Bitcoin, and possible applications are endless.
(Edited for clarification.)
P.S. If you happen to want to work on such a standard, I suggest that the best place start a collaborative effort is http://dot-bit.org/
. Check the draft specification for domain name entries