I'd like to add to Simon's comments and say that our build box is almost useless to us at the moment. we currently have 27 "broken" builds, but 5 minutes ago it was a lot higher. I kicked off a build for each of the broken jobs & about 6 or 7 started to work again, others are still running and will no doubt bring that number down lower again.
I know though that when I come in int he morning the wallboard will be a sea of red and I'll no idea which are actual broken builds and which are caused by this problem. We have over 100 builds and at present ~30 are showing as broken. Some are config issues because we have just migrated from CruiseControl, a couple are genuine failures and others are caused by this bug, but without going through each one, I can't tell which is which.
I'd argue that this needs to be a higher priority than major, it pretty much means we have to turn off publishing for our cobertura/clover based reports.