Nice. I've done something similar myself but I didn't take it exactly in the same direction. I leave much of grouping, wrapping, appending work to my own template engine layer. Is the source to your DSL available?
Yeah I would normally never mix the templating/html w/ the data processing but I was trying to stick to the example but w/ one line hah. Right now it is part of my new web framework which is very much a work in progress but available on http://voltron.googlecode.com the relevant code for the Array dsl is under Model/Type/Array.php and FluentLambda.php and the constant declarations are in bootstrap.php - again total work in progress so things are not as clean as they should be just yet.
