The new iPhone iOS 4.0.2 update was just released along with the iPad iOS 3.2.2 at the same time. 
This specific iPhone update has been released in order to fix a major security issue. As the newest iPhone JailbreakMe method was released, it realized a major security flaw, which could allow malicious threats to reach your iPhone; iOS4 4.0.2 iPhone Update deals with that specific security flaw that is associated with viewing malicious PDF files. While it doesn’t necessarily add additional flavor, the security fix is rather important.
iPad iOS 3.2.2 also treats the flaw in the same way.
It should be noted that the previous Jailbreak and the latest Ultrasnow Unlocking have not yet been released to treat the newest iOS 4.0.2 update.
From Apple:
iOS 4.0.2 Update for iPhone and iPod touch FreeType
CVE-ID: CVE-2010-1797
Available for: iOS 2.0 through 4.0.1 for iPhone 3G and later, iOS 2.1 through 4.0 for iPod touch (2nd generation) and later
Impact: Viewing a PDF document with maliciously crafted embedded fonts may allow arbitrary code execution
Description: A stack buffer overflow exists in FreeType’s handling of CFF opcodes. Viewing a PDF document with maliciously crafted embedded fonts may allow arbitrary code execution. This issue is addressed through improved bounds checking.
IOSurface
CVE-ID: CVE-2010-2973
Available for: iOS 2.0 through 4.0.1 for iPhone 3G and later, iOS 2.1 through 4.0 for iPod touch (2nd generation) and later
Impact: Malicious code running as the user may gain system privileges
Description: An integer overflow exists in the handling of IOSurface properties, which may allow malicious code running as the user to gain system privileges. This issue is addressed through improved bounds checking.
iOS 3.2.2 Update for iPad
FreeType
CVE-ID: CVE-2010-1797
Available for: iOS 3.2 and 3.2.1 for iPad
Impact: Viewing a PDF document with maliciously crafted embedded fonts may allow arbitrary code execution
Description: A stack buffer overflow exists in FreeType’s handling of CFF opcodes. Viewing a PDF document with maliciously crafted embedded fonts may allow arbitrary code execution. This issue is addressed through improved bounds checking.
IOSurface
CVE-ID: CVE-2010-2973
Available for: iOS 3.2 and 3.2.1 for iPad
Impact: Malicious code running as the user may gain system privileges
Description: An integer overflow exists in the handling of IOSurface properties, which may allow malicious code running as the user
to gain system privileges. This issue is addressed through improved bounds checking.
