Huzzah! That is some tasty news right there. I've always felt that their films lack something when they're not together... Jonze brings such a convincing authenticity to Kaufman's craziness and I love the way his camera probes down tunnels and through swamps.
Also, the ending of Being John Malkovich is my favourite of all time, along with that of Withnail and I.
I recently finally saw 'eternal sunshine of the spotless mind' too...admire Kaufman's writing very much! I think they create pretty awesomely well independently but the combination is a whole explosion of awesome. no way am I all that knowledgeable about their work but it seems both also have that congruence to their artistic vision, true artists!