According to a warning post by Bigboss using the leaked iPhone 3.0 OS is not profitable for non developers. Here is the reasoning

• The iPhone OS will probably expire every couple of weeks. If you are out and need a phone the day it expires you are screwed. You will not be able to use the iPhone until you restore to the “upgraded” version. If the current version is “leaked” (meaning you are not a developer and got it through unofficial means), there is no guarantee you will have access to the next beta to keep the iPhone running.
• The beta will have compatibility issues with some apps.
• You will not be able to jailbreak your beta.
• If you want some of the new features, read this post on how to use them on a 2.x.
• Your 3g baseband will be updated, and you cannot go back. Yellowsn0w on 3g will also stop working. There will be no fix for this. It is permanent!

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