Actually, the Galaxy Tab 8.9 was supposed to be released as a small version of the Galaxy Tab 10.1 already in July. Then there was a rumor that Samsung would release two versions of Galaxy Tab 8.9 due to display availability problems. And now the postponement of the Android 3.1 until mid-August.
After all, the larger 10.1 version is supposed to be released as planned, o2 wants to add the tablet to their program this week. Whether this will actually work is also still open.