When using the latest nightly, the Google Maps JS does not work anymore.
The JS Console says: Error: HIERARCHY_REQUEST_ERR: DOM Exception 3
It works fine in current Safari and Firefox.
Confirmed with a local debug build of WebKit r21473 with Safari 2.0.4 (419.3) on Mac OS X 10.4.9 (8P135). Does not occur with shipping Safari.
Note that there should be red "pins" on the test page which don't appear when this error occurs.
Safari 3 Public Beta also has this bug - 3.0 (522.11)
In the current nightly, this problem is solved...
Safari beta seems to use an older version of Webkit then the current nightly.