The only problem with using standard array notation for arc is that [] are already tied up for anonymous functions.
However, I think that too much syntactic sugar like this will end up damaging arc. Partly due to aesthetic reasons, but mostly due to the fact that each user has a different view on aesthetics, and adding too much will just exacerbate the "everyone has their own version" problem.
hmm, come to think of it, I've never used my table literal syntax {...} myself in a program. I wrote it so that I could write out and read back tables, which I use all the time, but that would work just as well with some long syntax like (literal-table k1 v1 k2 v2 ...) which doesn't use up precious syntax characters like { or #{.
