updated 09:41 am EDT, Wed May 30, 2012
Purpose of downtime unknown
(Updated with Nest thermostat info) The online Apple Store underwent some extended downtime overnight, checks show. Reports of the store going down first started late yesterday. Though it returned briefly without any changes, at some point the store went down again, only coming back shorty after 9AM Eastern time.
The reason for the downtime is uncertain, since the only prominent items on the store are promotions for Father's Day and graduate gifts, which would normally be quick site updates. Apple may simply have been making behind-the scenes changes, or struggling with technical problems. No new products are expected to show up on the store until at least June 11th, the beginning of WWDC 2012.
Update: The change appears to be related to the appearance of the Nest Learning Thermostat on the store. While it costs $250, the device can be controlled remotely via a Mac or an iOS device, and takes its name from its ability to self-program. It can reduce energy use when people are outside of the house, for instance, and store preferred temperatures. People can create personalized schedules, and see a history of heating and cooling activity.