Apple is offering developers a Tiger Early Starter Kit through the Apple Developer Connection (ADC).
The release of Mac OS X 10.4 Tiger is expected "in the first half of 2005". According to Apple the Early Starter Kit will give developers "everything you need to deliver revolutionary Tiger products to your customers".
It costs $500 and includes pre-release versions of Tiger and Xcode 2.0 and Gold Master versions of Tiger and Xcode 2.0 when available; downloads of the latest Tiger documentation; direct, one-on-one access to Tiger support engineers; and special developer discount on the latest Apple hardware. ADC Select membership for a year is also included.