So I've waited upon upgrading to Snow Leopard. And now I have also waited before upgrading to OS 3.1 on the iPhone. Judging by the Apple Forum, waiting is the thing to do. First of all, updating to 3.1 apparently destroys your Enterprise Exchange settings that push email in the workplace. Additionally, there is a large question about battery life that has become prominent. Not to mention frequent crashes.
Boy, does this sound like memory leaks or what? mmmgh, Lifedrive 2.0? I think that the problem with the frequent crashes has to do with the now implememented push notification service. Apple has allowed some of the software developers to go out of the sandbox and get a little taste of the OS core. Something that has long separated Mac programming from either Windows or Palm/Handheld programming. Palm had the same issues with crashes with almost every update for the same reason. This worsened when they decided to use a disk drive in their Lifedrive device. NVFS (Nonvolatile file system) was a bust! It seems that Apple may be having the same problem with so many different programs -- 75,000 at last count, vying for attention, many of these programs may be trying to access memory slots that are actually empty. Additionally, with Push Notifications, you are introducing background task management, further causing issues with memory leaks.
The only thing that I would want OS 3.1 for right now is MMS. I have been dying to have MMS for the longest time, but I will not download OS 3.1 until they have all of the wrinkles ironed out. Additionally, I will stay with 3.01 until I can be certain that I will not lose my work email as well.
Word to the wise: Do not do an upgrade until you see 80% No-Negative comments on the Apple forum.