I regret that I am only allowed to give you one "like" for this - you nailed it - this keynote will be extremely interesting, not so much because they introduce a flying car or a MBP that can travel through space and time (neither of those are likely), but to see exactly what they do with these rumored changes, and how they explain their reasoning. I can pretty much guarantee you their reasoning is not, "we removed the headphone jack because we're idiots" (even though that's a popular line of thought on this forum). They feel there is some benefit to what they have done. I'm willing to believe the headphone jack is likely going to be removed (the tea leaves all seem to indicate that), but what we don't know is why. And I'm quite eager to hear their explanation.
Folks keep bringing up floppy disks, but the more accurate comparison is USB. When the first iMac came out with only USB ports, there was very little support for USB in the industry, and a huge percentage of industry watchers thought they were completely nuts and complained loudly about Apple's poor judgement - in retrospect, I don't think anyone would complain now that we're using USB instead of serial and parallel ports.