I previously blogged about the lack or rhyme or reason to AT&T's seemingly random iPhone 3GS upgrade eligibility policy. Before today most iPhone 3G owners that purchased their phone on or around launch day (in July 2008) had to pay a $200 "early upgrade" penalty (read: $399/$499) to get the iPhone 3GS on Friday.
AppleInsider clarified things slightly saying "iPhone customers who spend more than $99 a month per line are generally eligible for an upgrade between 12 and 18 months into their contract."
All that changed today when AT&T changed its iPhone upgrade policy:
We’re now pleased to offer our iPhone 3G customers who are upgrade eligible in July, August or September 2009 our best upgrade pricing, beginning Thursday, June 18.
AT&T also cautions that its upgrade eligibility tools will reflect this change tomorrow – Thursday, 18 June.