Icons are reportedly sometimes disappearing or representing the wrong application. That’s not as catastrophic as a lightly baked piece of technology, but it’s certainly a nuisance for a gadget promoted for ease of use.
The iPhone FAQ suggests a couple of fixes. One involves removing the offending Apps and reinstalling them through iTunes. Resetting iPhone settings could also do the trick (by navigating to Settings -> General -> Reset -> Reset All Settings). If all else fails, a system restore may be necessary.
Some users have also reported short battery life in the 3GS, though it’s possible they’re just getting a little too comfortable with phone’s more hardware-intensive uses, such as gaming. Apple has released an application allowing owners to monitor the problem.
As for the overheating issue, Apple has remained silent since the news broke. It’s possible that reports of discoloration are overblown, as no other reports have emerged with evidence, but there’s no shortage of users saying the phone at least gets hot to the touch. In the past, Apple has been able to fix hot hardware with firmware updates, at least for its computers. With more than a million 3GS phones sold, a fix may be that simple. Otherwise, we’re looking at a wave of returns.