I found another DVD that was empty and burned a much more recent source disk of Windows 7 x64 that also had SP1 on it. I also made a bootable USB drive, which is what I usually use for installing any OS, but just to make sure, I tried re-configuring Boot Camp again with the new DVD and voila, everything went fine.
It had even let me do the whole thing with my MBP in clamshell (closed lid) mode because every now and then, I still forget that my 27" Cinema Display is not the iMac I had before. This MBP + Cinema Display solution works incredibly well and so does OS X 10.7 Lion. ;-)
(Mid-2012) 15.4" MacBook Pro w/ IPS Retina Display | Quad Core i7-3720QM 2.6GHz / 3.6GHz Max. Turbo | 16GB DDR3-1600MHz RAM | 256GB Samsung 830 SSD-based NAND Flash ETA 9/5