I haven't bought anything and, as a result of the GSL, I may never.
While I like some of the 4e changes on the character creation side, I dislike too many other things to want to run or play 4e at this time.
Normally, I would wait to see if third parties fixed what I don't like just as they did with 3e. However, I am not happy with the GSL restrictions, WOTC's cancellation of the d20 license, and the result where some 3e companies are having to choose discontinuing excellent products either to produce 4e versions of their 3.5 products or just to avoid the hassle of updating products to use the OGL license.