The new code update (3.1) for the iPhone, to be honest, doesn’t seem to offer a lot of incentive to upgrade. Well, with the exception of the security fixes that are in the mix.
From ZDNet:
Apple has released security patches to cover serious security vulnerabilities in its iPhone, iPod Touch and QuickTime products.
The most serious of the vulnerabilities could lead to remote code execution attacks that give malicious hackers an easy way to hijack computers and mobile devices.
Then if you do update and are jailbroken, next comes the brick. Currently there is no jailbreak yet available for this revision of code.
From C|Net:
If you’re one of the millions of iPhone users who’ve Jailbroken their iPhones or iPod Touches–the desktop hacking trick that allows you to use non-Apple approved apps, access the iPhone’s file system, and other tweaks–you’ll want to hold off on the latest software update (3.1) that Apple announced today. Updating your iPhone or Touch will break your Jailbreak, meaning any services and apps you’ve installed via Cydia will be gone, as well as Cydia itself.
So, until there is a “fix” be aware that you won’t be able to run Metasploit et cetera if you upgrade.
Otherwise…