The most recent email to customers from Rackspace, the Texas Web host whose datacenter outage in Dallas downed some of the Web's most useful websites:

Nov. 12th 11:30PM CST — As of 10:50 p.m. CST, all DFW servers that were proactively powered down earlier this evening, to avoid overheating, have now been powered back up. The Data Center Engineering team has been working to resolve the power issues caused by tonight's traffic incident. The team is preparing to transfer machines affected by tonight's power outage from generator power back to utility power. The servers and devices that were affected by the unrelated event over this past weekend will remain on generator power. We anticipate transferring the machines affected this evening back to utility power within the hour and expect the transfer to be non-disruptive to customer environments. We apologize again for the inconvenience these events have caused and have all hands on deck working fanatically to minimize the impact on your business.
Previously: Rackspace outage was third in two days