Well, I am overweight, and my specialist didn't really mention anything. Although I made sure to point out that I had lost about 10kgs up to that date from where I started, and weighed less than when I got pregnant with Bethany.
At my last appt, the only thing he said about my weight was that if I could lose more it would be great, as that would be sure to help with TTC. It wasn't said in a hurtful way at all. Just repeating the facts as I already knew them.
Before my first appt I was paranoid about him commenting on my weight, but it turned out to be a non-issue.
But as Jess said, it would probably depend on how much overweight you are, and even possibly on the individual specialist. I know of quite a few overweight girls who were ok'ed for clomid.