According to GM Inside News, the next Escalade will be built on a modified Lambda platform released sometime in 2012 as a 2013 model. Hurry up!!!
Personally I wouldn't bet on seeing a new EXT. Sales volumes just won't support it in todays market. JMHO
That's actually old information. I found newer articles when I was searching recently that say GM decided its customers would be best served by continuing the full size SUVs as they are today. I would expect to see a redesign based on what's there now. This is unfortunate, because if they really DID move to Lambda, our older trucks would then hold their value really well, as they'd be the last TRUE full size GM SUVs.
Of course, GM learned from all the leaks last time to be very cagey about information on GMT1000 (or whatever it will be), so if gas continues an upward trend, the project could be delayed indefinitely, or the Lambda thing could pop up again. Either way, I've heard that the release date would be 2012 as a 2013 model. The GMT900s would be pretty damn long in the tooth by 2014! And it makes sense, because GMT800 SUVs came out in 2000 and were replaced in 2006 as '07 models. Again, fuel crises could delay the next launch...
One thing you CAN almost count on is that the Expedition and Navigator are not likely to ever be refreshed or redesigned. Ford has absolutely ZERO plans for that market.