[DaFranker]

I will weigh in for the name-changing here as well. The technical issues aren't that big or complicated (well, assuming LWD is either 1: Good at migrations if using relational DBs, or 2: Good at unit testing and writing robust document modification code if using something like MongoDB) compared to some other feature requests, so public identity vs usefulness becomes the real issue.

So on that, here's a quick and dirty list of techniques I've seen used (or used myself) related to this. Note that I don't necessarily endorse or recommend them, and some I would actively protest against.

1. Keep and display a list of previous aliases. e.g.: Steam does this. Can still be confusing for the user in many cases if used on its own.
2. Keep track of every single time any user sees any other name; which name, where, when. When a name is changed, flag it for every user that has seen a previous name of this user, and show them a message to bring the name change to their attention next time they see the (new) username. I hope I don't have to explain the performance and data-complexity issues. No one has ever used this with more than 100 users, AFAIK.
3. Notify everyone the next time they see the new username, whether they've seen the old one before or not. This can lead to a storage requirement scaling by O(i*n^2) in the worst case, but the nominal space remains insignificant compared to the oodles of data RealmWorks is already handling.
4. Have separate username and display name. Looooooots of places do this. Easy, simple. Doesn't help the user identify authors at all. Confuses the hell out of everyone when a user changes names frequently.
5. Use a "karma score" to maintain accountability throughout name changes.
6. Ask users to create a different, separate, unique, unchangeable, tied-to-primary-key "Publisher Name" which will be displayed for any content they publish, and which they can use (or must use?) for comments / discussion regarding this content.
7. Make the display name / username changing process slightly more difficult / less convenient. This makes use of the well-known phenomenon of "trivial inconveniences" where humans demonstrably do something a lot less if there's even one trivial inconvenience they have to deal with first before they can do it (sometimes better known as the opt-in/opt-out dilemma).
8. Require a total wipe of the user's profile / public persona / all content. Please no.
9. Require moderator approval. Long processing delays.
10. Public announcement of every name change in some visible place, like a front page.
11. Let users "flag" accounts for themselves, as per Kate's suggestion above. Flags persist for the account, not the username.
12. Let users "flag" accounts or content for moderator attention.
13. Show content bought from this author previously.
14. Let users easily see the "Account Name" somehow, while only showing the Display name by default, again as per Kate's above and what some places like Paizo's website do.
15. What Wikipedia did. Anyone can clean up the garbage and elect themselves to receive a warning whenever changes are made to something. More suited to a wiki format than a marketplace format, obviously, but maybe something can be learned from it.
16. Somewhat similar to requiring moderator approval: Only change usernames through a support request. For bonus points, demand that they actually send an email directly to support (rather than use the support ticket form everything else uses), and that they explain the reasons why they want to change their username.