Prior to Star Wars: The Old Republic's launch in December, BioWare will be implementing new security measures to prevent players' accounts from being compromised. For starters, they'll be forcing players to change their passwords the next time they log in.
"All accounts created on or before October 21st, 2011 must reset their password to meet the new security standards," said BioWare. "Just like for any other user account you have, changing your Star Wars: The Old Republic password on a regular basis is one of the simple measures you can take to protect your personal information."
If memory serves, your Old Republic password needs to be a combination of letters and numbers. Additionally, it needs to have both upper case and lower case letters. There's probably a length requirement in there as well.
BioWare adds that your SW: TOR password is linked to EA.com and Origin.com. Your new game password, therefore, will be your new password for those two sites as well. It's just added incentive for making your password as strong as possible.
"We will implement the reset within the next few weeks, so look for a reminder email from us," said BioWare.
The Old Republic will launch on December 20th. You can start playing a few days early by pre-ordering.