I agree. It removes a lot of redundant characters. There are quite a few errors in the example (unless I'm missing something), but it sure looks a lot better, and the correct syntax would remove just as many (just be formatted a little differently).
Now this'll get me stoned, but what about combining it with a bracket pair that switches on infix? Here's the canonical factorial example in 3 views, implicit brackets on indentation and infix, implicit brackets on indentation, and standard Arc:
The infix looks nicer (to me, but I'm also a non-lisp programmer that understands how lisp works), but probably isn't worth the cost of adding a whole new language element, not to mention precidence rules into the language itself. Representing longer math though it would probably get more and more succinct. I have to say, I'm really taken with the whole implicit brackets thing. The strong Python feel helps with readability (I use Python day to day).