At the 2006 NAIAS(North American International Auto Show), GM announced the Tahoe Hybrid and confirmed the system would make it to the Escalade line in the 2008 model year.
The Escalade with have GM’s new dual-mode hybrid powertrain with electric motors that can provide assist at any speed. Fuel economy benefits are expected to be 25% over the conventional model (which is rated at 21MPG highway) so expect an Escalade that gets aproximately 25MPG.
No word yet on if this hybrid Escalade will be available in all versions (EXT, ESV, and standard Escalade). We’ll post more as the details are released.