Noted, I need to take a closer look at that. I've been pondering for quite a while what I should move on to after Python - Scheme would be an alternative, but after my longer time with Python, it somehow feels too verbose to me.
Somehow a not entirely unimportant factor that the Lisp community likes to ignore: names shouldn't be too long, otherwise you'll wear out your fingers typing. Sure, with macros you can make things more compact, but that's not what macros are for. A language with a script orientation should help you formulate your program quickly. In scsh, for example, that's far from the case.
However, when I look at the language definition, the whole thing is a bit strange. Many areas feel somewhat unfinished and un-lispy. Some of the concepts (e.g., exception handling) are rather primitive. Also, the foundation on heavily side-effect-oriented programming (due to symbols being used as hooks for everything and anything) is inelegant. And last but not least, the death blow: dynamic scoping. While cushioned by lexical namespace assignments, still: dynamic scoping is almost always more reason for trouble than joy.
Other aspects, however, are quite appealing, especially the very lean language scope and the few but efficient basic data types.
The syntax should become somewhat more logical - for example, marking all destructive functions with !, marking all property checks with ? - that's compact to write and easy to remember. For instance, the choice of set-nth for the non-destructive and nth-set for the destructive variant of changing the nth element of a data structure isn't really memorable and begs for confusion.
All in all, a clever idea, but probably less of a grand slam than it's made out to be. More in the class of Emacs Lisp - script Lisp, but a bit hacky.
At Lambda the Ultimate - Programming Languages Weblog there's the original article.