I had the transmission oil cooler and the hoses in my van replaced this summer. There was not a puddle, but the bottom of the pan was wet with transmission fluid.
I second the suggestion to check both the transmission and the power steering fluid levels, as both may use ATF+4. However, in the 2001 model year, I don't believe they had yet switched over to ATF+4 in the power steering system, so unless it was serviced by a dealer, it probably has regular old DOT Power Steering Fluid in it. If you check the Power steering and it has clear or grayish liquid in it, your leak is definitely the transmission or transmission cooler or hoses.
2005 Dodge Grand Caravan SXT, 129K mi.
Former owner of:
1988 Dodge Caravan SE, 2.5L I4 (1988-1995, 99K mi); 1995 Plymouth Grand Voyager SE "Rallye", 3.3L (1995-2004, 169K mi); 2003 Grand Caravan Sport, 3.8L, (2004-2008, 106K mi), 2008 Nissan Quest, (2008-2010, 25K mi)
2008 Lexus RX400h (Dark Gray), 112K mi; 2005 Hyundai Elantra GT (Blue), 89K mi