Will I be jailbreaking my iPhone 4?
I'm afraid not, sadly. My nice shiny new iPhone 4 will be jailbreak free. Completely and utterly. To the point that I'm doing a full restore and not restoring my backup, as it contains some preferences and whatnot left over from the jailbreak of my previous 3G. The only thing that's being copied over is the record of my 6,200 SMS messages that I've built up over the course of 3 years, and I'm doing that by plucking out the file from one of my old backups and then dropping it into a new backup and restoring from that.
It sounds long-winded, and it is, but I want this new iPhone to be completely untouched by the taint of jailbreaking. It just isn't worth the hassle any more. All the flaws that used to require a jailbreak seem to have been fixed by Apple nowadays. MMS, Copy/Paste, multitasking. It's all covered. Even the notification thing isn't major any more since fast app switching means you can reply to a text and be back playing angry birds in 2 seconds.
Quick summary: After 3 years of iPhone ownership the reasons to jailbreak have been reducing gradually. At this point I don't believe the benefits outweigh the hassles of avoiding updates, software glitches, extra fiddling and having to restore if I ever have a problem with the phone.
Update: Copying the SMS record from my old backup to the new one didn't work, it seems there's some kind of checksumming done on the backup as a whole entity rather than the individual components. On the plus side though I have noticed a massive improvement in battery life. I'm getting through a full day with ~60% left consistently. Which is nice.