Remember - if your whois sucks, or is not easily available, you'll end up getting alot of requests for contact information to domains and that takes up valuable time. So a good working flexible whois strategy saves you time and makes your tld registry more attractive to the end user and potential domain name holders. You may also want to consider some policies for your whois information. Whois service, as I mentioned, assists administrators in resolving network problems. However - as we are all aware many people are using whois for data mining.
Some people are against data mining.
In many instances data mining almost always ends up in spam. So you may wish to consider putting limits on how many whois records can be access by a client within a specific time period. This should discourage data mining efforts or potential abuse to your registry. Privacy is also an issue you might want to address. GOD registry allows users to maintain a private record flag.