Several reasons!
1) Dave asked for some FAQ-age about OpenID a few entries back, so I thought I'd offer that as a starting point for whatever will happen here as far as userdocing OpenID goes. I make no claims that it's adequate (or even good), but it's available.
2) Since this is a cross-site feature, everyone, DJers and LJers alike, would benefit from having good documents on every side. That's something that probably could have happened a bit better when the RSS features came about, but well... I wasn't FAQing for DJ at the time, so yea... here we are If anyone cares to look over the FAQ I wrote and point out any maladies, weaknesses, or blatently incorrect information, it would be greatly appreciated. Or anything important that's missing because I didn't come accross it when testing the features.
3) You guys like me (at least some of you) and want to see me succeed! And remember, it's for the good of the children!
note- dj will begin supporting OpenID after the overnight code upgrade. In the meantime, for testing/checking-out purposes you can use trinary.deadjournal.org (feel free to spam http://trinary.deadjournal.org/users/mismatcdsoxrok/)
Thanks guys
(and the obligatory, if you find this terribly off-topic, plz flame/delete/ban).
(oh- and everything i know about openid i learned this morning- so go easy on me)