According to an Edmunds member:
New Info on Lexus GX 470 from NY Auto Show
1) 2005 Lexus GX 470 scheduled to arrive 12/2004
2) The 2005 V-8 will have VVT-i [Variable Value Timing with intelligence] on the same 4.7 L block; increasing HP and torque and, I guess, it will deliver better mileage
3) starting sometime this summer, a towing option will be available with KDSS [Kinetic Dynamic Suspension System]. Apparently, the only reason it isn't offered now is that the location of KDSS interferes with the placement of the towing hitch receiver. A redesign will fix this problem.