I recall (the last time I started and ran mine <img src="/forums/images/graemlins/zombie.gif" alt="" /> <img src="/forums/images/graemlins/lol.gif" alt="" />) when started cold that mine idled pretty high also until it warmed up but once I dropped it into gear (Automatic) it didn't stay at that high but dropped down significantly (probably 30-40% IIRC).

If it put it right back to park/neutral it would kick back up though.

After it warmed up it ran at ~700 rpm.

IIRC it always behaved this way.