As much as I respect Ola Bini's projects, I have to ask: what reason would one have to use Seph instead of Clojure? They seem to have the same design goals (homoiconicity, immutability)

you dont like lisp syntax? you want to do prototype based OO? they aren't identical. they may share some features but not all features. its sort of like asking back in the 90s- why would i use python instead of perl.

I'm curious to see the syntax (he says it will be homoiconic) and how that translates into the mechanism for manipulating the AST. This is the raison d'être for lisp's syntax.

From the post, I'm assuming it will be similar in syntax to Ioke. You can see its syntax at http://ioke.org/

He mentioned it's similar to Ioke, which looks like this

  if(42 < 43,
    "wow, math comparison works" println,
    "we have some serious trouble" println)

Is there an example of AST manipulation?

Congratulations.... Since it's still "pre-announce" phase, I'll point out the collision with "Ceph" (http://ceph.newdream.net/), which may or may not be of concern to you and the team.