Upgrading Jailbroken iPHone 3G to 4.1

[bmaxam]

Hi, I recently downgraded my iPhone 3g to 4.01 and jailbroke it using the jailbreakme pdf exploit. The speed of the phone is horrible and now am more than willing to lose the features that I gained by jailbreaking it to update to 4.1. My question is - am i going to brick my phone by letting itunes update my phone to 4.1 when it comes out next week or do I need to do something special to remove the jailbreak first? Your responses will be greatly appreciated.