Apple is grumbling up to a release of tiger sometime soon.
Developers like me are not told the exact date.
We find out the day apple releases it!
Just like everyone else

But I tested on the latest build a couple of weeks ago and parts of opengl were still badly broken.

So apple may end up releasing something that doesnt work very well for this.

DONT install Mac OSX 10.4 when released and expect Catalyst or Pixelmad to work!
There is a large probability that they wont work properly.
This is a very big change for apple.
Not a minor update