Has Java 1.6 SDK been released for mac? I can't seem to find it...
Yes, but only for 64-bit Intel-based Macs, i.e. Macs using Core 2 (duo or solo) or Xeon chips. The original Core chip is not supported, nor is any PPC chip. Also, Java 6 is currently Leopard-only. The update should appear in Software Update, if you have a compatible Mac and recent-enough OS version.
Here are the release notes for the first update. And here are the second update's release notes.
Apple released 1.6_07 about a month ago. Look for 1.6_10 around about 2010, given how long it took them to get 07 out. And as already stated, it's only for 64bit Macs.
If you dont see it, you may have to go to the Developers Connection for apple. If you want to download Java, you may have to signup for a free account.
As msanders said, SoyLatte might be good in a pinch, but be aware that the latest version of SoyLatte, 1.0.3, is Java 1.6.0_03. The most recent version from Sun is 1.6_10. That may not matter for what you're doing, but you should keep it in mind.