This anouncement actually posted on lodestone on May 23rd 2013. However, I haven't seen anyone posting this announcement at this forum. Therefore, I decided to create this thread for future reference.
Lodestone Announcement 05/23/2013
Windows XP Support Information
Thank you for your continued support of FINAL FANTASY XIV: A Realm Reborn.
With the announcement that Microsoft(R) will no longer be supporting Windows XP from April 9th, 2014, we regret to inform you that Final Fantasy XIV: A Realm Reborn will no longer be able to guarantee support for Windows XP after the Beta Test Phase 3, which is planned to start early June.
Due to the fact that Microsoft(R) has already completed the support life cycle of this product, we have found that continuing support for this OS is a difficult proposition. We have instead decided to put more focus on support for Windows 8, and we hope everyone will understand.
Although support for Windows XP will no longer be guaranteed after the Beta Test Phase 3, our development team will still build from the existing platform. This does not mean that our users will no longer be able to play using Windows XP, and current users will still be able to play using Windows XP.
We will do our best to have compatibility with our Software Updates from this point forward, but there will be instances where we won't be able to guarantee support due to Windows XP issues.
Thank you for your understanding and cooperation in this matter.
Edited, May 30th 2013 7:23pm by ilwhana