I read the comments at the link you provided, and I can see that you guys have thought this thru. I can't say that I agree with your conclusions, but I don't think there's much I could say to change people's minds, since I happen to be one of the people in the minority that refuses to allow any updates to my computers to happen without my explicit consent.
Then again... :-) Perhaps this function should be tied to the automatic updates setting? If updates are done automatically, do as you do now, but if not - if the update is being done because the user himself initiated it - the first-run page should be displayed immediately...?