From 9to5mac.com:
Adobe makes a compelling suite of creative applications, which are the de facto industry standard, but Adobe’s high price points have traditionally put off many prospective Creative Suite buyers. To make matters worse, a change in upgrade policy last year enraged customers as it pushed them towards pricier subscription-based offerings. Well, if you already own Adobe Creative Suite 3 or CS4, you are in for a surprise as the company just announced a special upgrade offer towards CS6 purchases. According to a blog post, special introductory upgrade pricing on Creative Suite 6 to customers who own CS3 or CS4 is available from the time CS6 is released until December 31, 2012.
http://9to5mac.com/2012/01/11/adobe-relents-announces-cs6-upgrade-offer-for-cs3cs4-owners/