It was a nice little cameo. I also loved the shout out to Lennie Briscoe. Four years later, I still miss Jerry Orbach.
They've certainly covered some maudlin territory with Lt. Van Buren's cancer storyline. The emphasis on this more than anything else makes me wonder if this is truly the last season for Law & Order.
With the reference to Curtis working in L.A. now, I wonder if they're perhaps setting him up for future appearances on the rumored Law & Order: Los Angeles