I think the saga of SW:TOR's launch and how they handled packed servers is an excellent cautionary tale for FFXIV. They had a ridiculous amount of servers, adding a ton of them to quiet the complaints of people wanting to play without waiting. Though I would not wish TOR's eventual population hemorrhaging on any other game, even if the population had tapered off more gently (as some player attrition is normal) they would have still had way too many servers. This resulted in most of them becoming sparsely populated, which then led to vicious cycle of players leaving because they didn't have enough people on their server.

In short, TOR's method for having a successful launch came back to bite them in the rear later. xD

That said, SE really needs to implement a proper que! That is one thing they could learn from TOR's launch.