1.) Rename classes in source code to reflect package name change.
2.) DataGrid::dump() should be either a.) renamed to reflect what it does (debug) or b.) changed into a new renderer (debug)
3.) It's not necessary to return $this from class constructors (ie. HTML_DataGrid_Column).
4.) I'd set autoFill in Column to a default of some sort ('n/a' or simply ' ') so HTML cells don't format incorrectly with no data.
5.) In setRenderer you should check the include with if(include()) and return a PEAR_Error if I supplied the function with 'foo' since the renderer does not exist (looks like the code to do this is there, but commented out).
I, personally, can't wait for this package to come out (I've been too lazy to write my own for quite some time). Thanks!