getComputedTextLength() works in Firefox but not Safari. This function is crucial for dynamic generation of elements that contain varying amounts of text. http://www.w3.org/TR/SVG11/text.html
Yep, it's definitely on the list of things to fix. Nikolas is currently working on finishing the rest of the text system before implementing these (rather simple) methods. I'm sure you'll see them in WebKit within the next few months. Thanks for the bug (and the awesome set of SVG examples!) *** This bug has been marked as a duplicate of 12290 ***