Any respectable PC monitor these days has HDMI input.
Many of us like to connect our laptops to our HDTVs, so thats a plus.
HDMI is also a smaller connection than DVI-D while carrying the same signal.
HDMI would be a HUGE plus in the MacBook rather than the costly mini-DVI that requires a $20 adapter for every single connection you want to make, plus additional adapters if you want to connect to a modern display or HDTV.