One thing to bear in mind for those who have kept an "acceptable" unit:
The issue with the screen yellowness and other assorted QC issues is MOST likely to be a hardware fault. Gamma can be modified in software, but I very much doubt that yellowness/unevenness can. That's the main reason I've returned mine now and am waiting. If you've kept a phone that's "good enough" then be clear that any remaining issues probably WON'T be sorted out by firmware updates.
Interestingly, the only thing that makes this situation livable for Apple is quite a few people now who are settling for "good enough" even when comparing their screens to a 3G with proof right there that there is a problem with their "acceptable" 3GS. The more people accept "just about good enough", the LESS incentive Apple has to fix this problem or take it seriously. We all have different ideas about what "good enough" is, for sure, but the effect of your decision might be interesting to consider.
I do wonder now if it's worth it to re-sign up for an 18 month contract with O2 after having to wait 1-2 months for this Quality Control mess to (hopefully) get addressed. By the time I re-sign up, if I do, it won't be all that long before the NEXT revision will be released. I mean 9 months IS a long time, but is it TOO long to wait out now for the next version.
Off topic(ish) but I have a SNEAKING suspicion that the next version will include an OLED screen for a few reasons:
1) By then, OLED will be more dependable in terms of longevity (or maybe not - this is Apple after all)
2) OLED will allow Apple to INCREASE battery life which might be essential next time due to an increase in processor speed etc.
3) OLED will also (and I think this might be a bit factor) allow Apple to release a RE-DESIGNED handset which is SLIMMER because of course OLED doesn't need a back-light. The Samsung Jet, an amazingly specified but horribly GUI'd phone uses OLED already.
I, for one, can't wait for a time when screens are a no-brainer in that they will ALWAYS be of a specific standard unless there a GLARING faults. The problem here is the erratic quality issues, which are often subtle and hard to explain/point out.
Shall I wait or shall I dive back in?