Information Retrieval Gupf

One of my ongoing research interest areas is in retrieval interfaces that allow more expressive and powerful statements of a user information need.  In that spirit, I wrote a minor rant last April about how the Apple iTunes smart playlist creation interface sacrifices functionality in the interest of simplicity.  One could only create smart playlists using a flat conjunction or flat disjunction of expressions.  See this screenshot:

Well, the times they are a’changing.  I just noticed that the newest version of iTunes (9.0) allows arbitrarily-nested conjunctions and disjunctions.  This ability to mix and match gives rise to much greater capability, and only adds the minimum of interface clutter and complexity, i.e. expression indentation and an additional (…) button:

I laud the change and improvement, and I feel that it is another step in the ongoing attempt to raise consciousness about the value of moving beyond barren and crippled-functionality information organization interfaces.  That is one of the core challenges of HCIR, and I see Apple now taking another step in this direction.