There has not been much done about the bug so, so far, there are only speculations about the bug. According to Robert Collins, the bug has been known to him for a couple of months now and he believes that Intel has known about the bug too, but Intel claims that it has just learned about the bug and is off researching it.
According to Collins, the author of the Intel Secrets page, the bug is a single illegal instruction and not something that would be deliberately coded into a software program so it will not be found in commercial software or in independently developed software. However, this instruction could be maliciously inserted into a small C program and be used to bring down a company's server computers, according to Collins.
More about the bug is yet to be found.