I cant imagine that MS would delay Win7 over a bug that only happens when you using a tool that means your system is hosed anyway.
If you are using the /r command that usually means that something is seriously wrong with your harddrive, so the utility uses that much ram in a bid to get done as fast as possible.
Umm, I use chkdsk quite often (on other peoples' disks admittedly)...
And apparently it causes system instability, which a process using lots of resources shouldn't. There could be a bigger issue that needs to be addressed.