VoIP peering technology review: request for information

I'd like to review any methods by which operators are currently exchanging e.164 telephony route information between VoIP systems (excluding SS7.) In the last ~1 year, I have not heard of any significant changes in the manner in which routes are exchanged; the typical method still seems to be Excel spreadsheets or CSV files. ENUM seems to be gaining some ground, with providers populating their own root servers, but I haven't heard of or seen a complete specification from anyone - it's been mostly rumor, so detailed implementation examples of ENUM use would be appreciated. Bonus points for telling me how this scales without a single root to bind them.

If you are using an automated method to inform your VoIP telephony "peers" of new VoIP-enabled DIDs or (more importantly) routes that you offer, I would like to hear about it, even if it's just a sentence or a link to go find more information. Do you use TRIP? XML exchanges? SQL over TCP? LDAP? I am especially interested in "accessible" methods that don't require significant capital investment in proprietary technology, hardware, or service provider products.

Just as important would be the topics of non-disclosure between peering entities and other political issues surrounding exchange of customer (specific) or route (general) data and the threat of unveiling your customer base details to your competitors. That discussion makes me think of the same arguments 10 years ago with BGP...

I am often asked to speak and write on the topic of VoIP peering (if there is such a thing) and I am trying to prevent being out-of-date on this quickly changing environment. I am not able to keep up with digging through the marketing foam to find the good information underneath, so I'm probably missing some interesting trends. All answers will be anonymized unless you specifically request the answers to be publicly attributed. Please reply privately; a summary of useful data will be sent back to the list(s).