With Intel's release of Haswell, many PC enthusiasts were awaiting to hear the news if the rumored USB 3.0 bug was indeed real, and did in fact make it to production. Intel's latest CPU may indeed come with a much more robust USB 3.0 controller baked into it, but it also is broken technology. Right now, if you attach a USB 3.0 device to a Haswell system and then at some later point the OS enters S3 standby mode - while the drives are still attached - and then resume from the S2 state, errors can occur. In other words, the brain of USB 3.0 loses its mind and everything from applications using that external device to data not saved may be lost. According to this non-exhaustive compatibility test, 14 out of 22 drives
didn't get along with Haswell.
While serious, this is not overly dire. Firstly, it does not affect USB 2.0 devices, it will not always cause problems with USB 3.0 devices and if it does, any application affected will start functioning properly once it is restarted. Of course, this will not help any data which was not properly saved to the device before the S3 state was initiated, but all things considered this bug is no reason to not get a new system. Intel is fully aware of it and a new bug fixed C2 revision is expected shortly, so only early adopters will be impacted by it.
Also, any Haswell chips sold now will in all likelihood be replaced free of charge once the new C2 revision is released, just as Intel had to do with the certain first gen. Pentium CPUs which had the dreaded FDIV bug. Until the C2s appear, simply removing the USB 3.0 before entering a low power state will alleviate this issue. Lastly, many 'enthusiast' motherboards should also be coming with secondary USB 3.0 controllers making these ports another safe alternative until Intel fixes this issue.