I've seen a few videos on the milling process and they didn't look fine enough to allow for SMD mounting. Maybe I'm seeing the wrong videos?
Or someone is using the wrong machine. Our guys make PCBs for SMT components on a Haas TM pretty regularly. Takes all freakin' day because the mill only has a 4000 RPM spindle (it's designed for machining, not PCB milling) but other than that it works great for small stuff. I know they've done 100 pin LQPF, I think some no-lead stuff, and smaller passives (0603 for sure, and I'm fairly certain 0402).
-j