when fatal bugs, or issues are reported, there is little communication from apple... alot people/companies depend on what apple is doing here
hisotrically, they announce new stuff, then ios is released about 1 week later (conveyed at the annnouncement)
this time, it was one day.
alot of us had apps already in testing and preparation, but depending on what features you might have used, some bugs occur that have either no workaround of nasty workarounds, and we need the GM release to confirm certain things and how to proceed
i cant talk about the issues i have faced in my job, but this 1 day notice has not gone off well
-- as an aside --
personally, my feelings towards apple has soured very much, and anecdotally, many friends who work in industry who have to deal with apple (apps, app store, safari etc) have soured on them too
when people say "apple doesnt care about developers" i can understand thier feelings somewhat...