http://www.macnn.com/articles/10/04/22/new.features.still.unclear/
Apple already testing Mac OS X 10.6.4
updated 07:25 pm EDT, Thu April 22, 2010
New features still unclear
Just weeks after Apple released Mac OS X 10.6.3, the company is already said to be preparing to test early v10.6.4 builds, according to iPhoneinCanada. The first test builds of v10.6.3 arrived in January, two months after the v10.6.2 public release.
New features of the fourth Snow Leopard revision remain unknown. The recent release provided improvements to QuickTime X, OpenGL support, 64-bit performance with Logic Pro 9 and Main Stage 2, and several other minor changes.
The release schedule for v10.6.4 is also unclear, although the public version is expected to arrive sometime in the summer.
Fresh-Faced Recruit
Joined: Jul 2001
Uhhh yeah... so what?
I don't understand why this is so surprising that Apple would start working on the next update immediately after releasing an update. I think it's a pretty common practice to decide what things are going to be included in an update, freeze the update, test and distribute it then start working on the next update including things that weren't including in the update you just released. Many of these MacNN articles are starting to feel like posting for the sake of posting with very little actual news. Of course that's just my $0.02, I could be wrong.