Is Ebert doing a regular commentary or just an introduction to the movie? The details didn't seem specific to what he was doing. Either way, since I missed out on the first set, this is major news for me because the art of Kieslowski has risen to a major importance for me.
I don't Kubrick wanted to be Kiewslowski. Kubrick was too much the adventuer in showing different worlds and visions along the lines of like Speilberg or Stone, but Kubrick identified that the approach to showing those worlds was in how Kieslowski presented them. Just action, and no underlining.
Regarding the Ebert thing, but first I don't want to sound like anti-ebert but, am I the only one who find this 'bonus' totally irrelevant? Obviously he might make an interesting one but I can think of at least a dozen other people who could introduce the viewer better than him, like Scorsese, Coppola, etc... At least (IMO) I would find a commentary by other director much more interesting since he knows what it takes to make flim.
About Kubrick, also think that he didn't want to be him or direct like him, what apparently he did say to Raphael is if he thought he could do something like Decalogue, and in fact Raphael wrote a series of short stories not necesarilly for SK but thinking of the possibility of him to direct them. I guess he hesitated about it for the long periods that took him to make one film let alone ten.
Here's a foreword that SK wrote to the Decalogue.
'I am always reluctant to single out some particular feature of the work of a major filmmaker because it tends inevitably to simplify and reduce the work. But in this book of screenplays by Krzysztof Kieslowski and his co-author, Krzysztof Piesiewicz, it should not be out of place to observe that they have the very rare ability to dramatize their ideas rather than just talking about them. By making their points through the dramatic action of the story they gain the added power of allowing the audience to discover what's really going on rather than being told. They do this with such dazzling skill, you never see the ideas coming and don't realize until much later how profoundly they have reached your heart.'