Might well be a lot hotter than the number I quoted. I did a quick, cheap "wiki" check on lava and came up with that figure. But lava flow has already been cooled by the ambient air and the adjacent earth crust, which is a LOT cooler than the lava itself.
Sorry, obscure reference. The mighty and omniscient Al Gore himself said the earth’s core was “several millions of degrees.”
http://www.youtube.com/watch?v=zMrxC-qEHb8
He was, of course, wrong.