I am thinking that it would be mostly useful for marketing/fanboy argumentation. Much like the whole "resistive screen, what is this, 1999?" thing.

However, I don't think the zoom circle solution on the N900 is optimal because it drags the page around at first. A pinch or dedicated space like on the HTCs is more accurate. I am sure that some people will like an alternative to the zoom circle. So a good solution on this may just become popular.