Apple iOS 4.2, which will bring multitasking to the iPad, improved performance to the iPhone 3G, and features like AirPlay and AirPrint to all, may arrive as soon as this Friday.
According to MacStories, an "inside source at AT&T" said that the update will be available for download on Friday, November 12, at 10 a.m. PT. And prior to that (possibly tomorrow), Apple will release iTunes 10.1.
Further evidence comes from iPhone Help, which cited the German blog iPhone-Ticker's discovery of Vodafone and O2 configuration profiles containing updated network operator settings predated November 12. (That's my takeaway of the somewhat murky translation.)
Needless to say, it's all just rumor at this point. However, historically speaking, an iTunes update usually does precede an iOS update by a few days. So if 10.1 does drop tomorrow, Friday may well be the day for 4.2.
We'll know more tomorrow and in the coming days, so be sure to check back for updates. In the meantime, hit the comments and let me know which iOS 4.2 feature(s) you're most looking forward to!