Firefox 2.03 will fix a lot of security issues but I am sure you didn't even know about them at the first place. However we advise you should install it as it is available as of yesterday.

This version fixed a FTP PASV port-scanning and that was the only mayor thing fixed in this release.

The 2.02 fixed far more issues including Privilege escalation by setting img.src to javascript: URI, onUnload + document.write() memory corruption, Embedded nulls in location.hostname confuse same-domain checks, Mozilla Network Security Services (NSS) SSLv2 buffer overflow, SS and local file access by opening blocked popups, Spoofing using custom cursor and CSS3 hotspot, Information disclosure through cache collisions, Improvements to help protect against Cross-Site Scripting attacks and finally Crashes with evidence of memory corruption (rv:1.8.0.10/1.8.1.2).

No matter how do you feel about this update we recommend you go for it as it will make you safer on the net.

You can read more about the release here.