Quote Originally Posted by MiRai View Post
Other than the obvious time difference on the server itself when using the /time command, the main difference between the two timezones will likely be:

Pacific will be hosted in the Los Angeles datacenter.
Eastern will be hosted in the Chicago datacenter.

While that's not necessarily true for the current Retail server list due to the repeated consolidation of datacenters over the years, I would bet money that they're keeping it simple for Classic. So, if latency matters to you, then choose accordingly, but I guess we won't know for 100% until the servers are actually up for early name reservations.
Traditionally it seems to me that servers in the Pacific Time Zone would allow the greatest number of people to play together as people can't realistically get off work earlier but can choose to stay up / start later.

For example Raids starting at 5:30pm PST (7:30 Central or 8:30 Eastern) or 6pm PST would likely be able to accommodate the largest cross section of Americas players.