It won't matter, because the exploit they found will work on any firmware update Apple comes up with because it is a hardware exploit. This means that until Apple changes the hardware in the iPhone there is no way they can stop the jailbreak.
Now I know dev team and it's members have repeatedly stated don't upgrade yet but I have no need for an unlock I only want a jailbreak and the proximity sensor issue is making me rip my hair out.. Now Is the exploit in the earlier baseband or will I be just as jailbreakable on my iphone4 with 4.1 and new baseband?
It's a bootrom hack and involves the processor from what I understand, so you won't have to worry about not being able to jailbreak your iPhone if you update now, the baseband doesn't have anything to do with the jailbreak. That being said, that is only what I understand from what I've read, I haven't heard anything about not being able to jailbreak in the future if you update to 4.1 now, but I still don't know 100%.
Yep! From what I understand, it is a hardware exploit that will work on all current iPhone 4, iPad, and iPod Touch 4g, so Apple will not be able to patch this exploit unless they physically change the hardware, and obviously they can't do that on our devices!