First a followup on the bug.  The bug is in the chkdsk.exe, a long standing Windows utility that allows you to check and repair your disks.  In order to activate the bug you must run the utility and then choose the -R option from the command line or the "Scan for and attempt recovery of bad sectors" on the GUI (not the default option).  The bug only occurs when scanning secondary disks or partitions -- something a lot of users don't even have.

While this is a bit of a problem for system administrators, it now appears that the bug isn't as bad as was initially believed.  Microsoft's newly appointed Windows President Steven Sinofsky took the unusual step of responding to one blog discussing the problem, Chris123NT.  As Mr. Sinofsky points out, "While we appreciate the drama of 'critical bug' and then the pickup of 'showstopper' that I’ve seen, we might take a step back and realize that this might not have that defcon level. Bugs that are so severe as to require immediate patches and attention would have to have no workarounds and would generally be such that a large set of people would run across them in the normal course of using their PC."

This is definitely a valid point.  There have been such bugs in past Windows OS's -- such as the Windows Home Server bug that corrupted data occasionally on a variety of normal reads and writes.  However, this is a utility that most users rarely run, and requires the user to specially select the second option.  Lastly, it appears that the severity of the bug varies -- on some computers it takes up only 90 percent of the memory, on others it crashes entirely.

Furthermore, while the biggest danger is likely that the flaw could be exploited by malicious parties who gained user level access to quickly swamp a  system, again this isn't necessarily of show stopping variety.  A hacker could just as easily open 200 copies of Microsoft Paint, which would also likely kill your RAM (with the nice addition of causing more visual annoyances).

Mr. Sinofsky says the Windows team is hard at work trying to track it down.  He states, "Some have reported (as above) that this specific issue repros and then goes away with updated drivers. We haven’t yet confirmed that either but continue to try. We just kicked off overnight stress testing of 40 machines of variants as reported by FireRx. We’ll see."

It looks like the RTM bug may be an example of an out of control feature.  Microsoft looked to give chkdsk more RAM, reportedly to help it run faster on modern systems with a lot of RAM.  Some are speculating that this feature broke and it now takes more RAM than it should.  What's interesting is that if true, this means that Microsoft is taking the opposite approach with disk checking as it is with Antivirus -- the free beta of Microsoft Antivirus had a smaller-than-average memory footprint.

A fair prediction seems that Microsoft has a patch on Windows Update for the utility by launch time and the users are minimally inconvenienced.  In the meantime, try not to select those specific options in chkdsk.exe, no matter how tempting they seemed.