I was the one who suggested that, and there is a pretty good arguement. Heck, you could argue that he's even better than the wildly overrated Zambrano right now. The only thing Zam has is the track record. Based on last year alone, I would feel comfortable saying Hill was better, and with him on the upswing, I'd take him over any Cubs starter for next season.
He's come a long way since the last time his name came up in trade talks on this board (for Kearns).
If you think Lilly's better, well they are close, actually really similar players with the FB tendencies, but Hill has a K advantage.