In addition to some optimization hotfixes, Mark Jacobs had some things to say regarding the recent city seige issues:

Currently, players may experience issues when attempting to queue into a Capital City instance. The queue may not fire properly or in some cases players may be sent to Character Select. While we work to correct this issue players are often able to get in eventually. In addition to this we are investigating issues where players are unable to respawn properly, players have reported that using the /reloadui command multiple times often corrects the problem.

Check after the jump for the full annoncement and the day's hotfix.

Hotfix:

General

• Implemented server optimizations which will greatly increase the server’s performance, particularly in open field Realm vs. Realm combat. With these changes player will experience significantly improved server response time and reduced lag when engaged in large-scale Realm vs. Realm  battles.

City Seige Issues:

Hi everyone,

Some issues have come to our attention since the release of 1.2.1 and we wanted to ensure you we are aware and actively working on solutions. Patch days can often create unforeseen issues that only large, real-time server populations can expose. While we work to eliminate these problems beforehand we sometimes don't find all of them.

Currently, players may experience issues when attempting to queue into a Capital City instance. The queue may not fire properly or in some cases players may be sent to Character Select. While we work to correct this issue players are often able to get in eventually. In addition to this we are investigating issues where players are unable to respawn properly, players have reported that using the /reloadui command multiple times often corrects the problem.

Lastly we are aware of cast bar issues players are experiencing throughout the game, in addition to those mentioned above we will have a resolution as quickly as possible. The server stability issues experienced last night should now be resolved with this mornings deployment, once again we apologize for the inconvenience this may have caused you.

While we constantly strive to reduce the impact of Patch Days, they are often a time of great change, know though that we'll always work to resolve any issues that arise during these periods as quickly as possible and ensure to keep you informed of our progress.

With that said 1.2.1 introduced many fantastic features and improvements, and we're excited to see many of you enjoying them as you work towards your new goals. But there's even more to look forward too as Beyond The Sands approaches and all should be prepared for the Land of the Dead!

Thanks everyone, and have a great weekend...WAAAGH!!!