I have just posted a nodejs corepure64 extension (wait a couple of days for it to be in the repository). This will allow nodejs to use more than 4 Gb of memory. I have posted the just released v0.10, I will wait to post it to the 32-bit repository since I have noticed that not all of the major npm extensions build scripts have been updated to work with the npm version bundled with v0.10.
/Simon