The likelihood of you "jumping right in" with nVidia in an engineering job is very unlikely. That's like going from Highschool football directly to pro football. Though you
may be able to score an intership or something when you're done w/ your bachelors or masters, but you'll probably need to start working for a small company.
Remember that nVidia and ATI are the premier chip makers in the world right now and everyone wants to work for them. Get your feet wet with a little graphics IP company or some other lesser known company that makes video chips for cell phones or something like that. Basically get some experience under your belt.
I doubt nVidia or ATI is hiring engineers straight out of college.
Take a look at this nVidia job posting for example:
http://careers.nvidia.com/pljb/global_jsp/applicant/DisplayJob/JobDetails.jsp?display=1&pljbHome=/nvidia/nvidiaemployment/applicant/index.jsp&id=879
"Minimum 4 years of industry experience"
Sorry bud, but that's not someone out of college. All the other postings are the same.
Weskurtz had a good suggestion about getting a business degree too. Those are usually easier to get into and can pay a lot more.