Eh, Zack was never a character I really felt anything for or against. I could have taken or left his departure.
Saying that, the way things worked out, in my opinion, it gave a little dynamic-ness to the show when they had their Intern-of-the-Week guys come in.
I gotta say I like the 'Country Boy' intern.
Gee I wonder why...?
But, I digress...