I've met with all of the big banks (including GS) and for the most part, GMAT and GPA have not come up directly, but they reference them indirectly. Several firms have said things like "we recruit for high mental horsepower" and "we go after pure athletes". Sometimes it's brought up in the negative, as in "you don't have to a 750 GMAT to land an interview", implying that it would be nice if you did. I'm quite certain that all of the big investment banks, and some of the top consulting firms will consider GMAT when setting their interview schedules. I do not know how it might factor into the final decisions.
I think of it like this. There's a direct relationship between the selectivity of a firm and the selectivity of a school. For example, most firms probably never bring up GMAT when they are recruiting at Harvard, because most firms would be happy to hire most anybody from there. At a lesser school (pretty much all of them) a highly selective firm will limit their interview list through various means, including GMAT, past experience, etc. Here at Darden (just my observations), it seem like most general management firms are happy to hire all comers. I think it's pretty clear that GMAT will be a major factor with the big 3 consulting firms, and perhaps with a couple others as well (Booz Allen requested resumes before selecting a close list for a dinner). GMAT will probably be a factor with maybe 5-7 of the most selective IB recruiters.
I guess it's pretty straightforward. If a firm is recruiting at schools around the country, they well be more lax at highly selective schools, and more selective at less competitive schools.