4.2 will be out shortly and hopefully an unlock about a week after that. I would suggest holding off until then. No point in going through the process of preserving your baseband just to find another update is released by apple...
didnt it have a PDF exploit that was dangerous to your private info?, well even if you upgrade to 4.1 you get better front prox sensor, tweaked signal bars, game center and thats all i can really think off the top of my head, and now with limera1n or greenpois0n you can still jailbreak, so ultimately its up to you