Cool! Keep me posted if you run into issues. I just did a test render to PNG at 60" x 48" at 300dpi, and it took my machine a while but it did complete successfully. I also tried setting the output to 600dpi at a regular 11.5x8 paper size and that worked. I think the 64-bit support has made this sort of thing more possible.
I do see quite a bit of jagginess - I’m not really seeing any AA in effect here.
Thanks,
Marc