I actually only watched parts of the match but the reason I said that is because he came to the net a lot, which I really like.
The stats were also very good. I think he had 44 winners to 33 UEs and won 30+ out of almost 50 points at the net.
Good stats indeed.
In the end of the first set against Verdasco he also came to the net and it reminded me of the Richie from MC 2005.
I think that's the sign he enjoys himself and gets more confidence.
The other very good improvement is his fitness. I was worried after his first round when he said that he hoped he would be ok for the next match but he proved he is solid now.
As you said, he really should improve his serve though.. It would give him free points and shorter matches.
Btw, did he call the trainer today?
I think as he gets more confident, he'll improve more.