Cool as the Excursion is, somewhat, I think it's a wise idea. It really should have been just an extended Expedition. Chevy is having tremendous success with their own line of large SUVs, so maybe they're taking heed. It's all about basing it off your full-size truck, not the heavy duty stuff. Allow me to ellaborate with some analogies (and I hope I'm structuring them properly- haven't done this since 8th grade)...
Chevy 1500 pickup : Chevy Tahoe :: Ford Expedition : Ford F-150 pickup
Chevy 1500 pickup : Chevy Suburban :: Ford Expedition : Ford F-150 pickup
Chevy 2500 pickup : No current model:: Ford Excursion : Ford F-250 pickup
...or something like that. The Chevy Tahoe is basically a shrunken Suburban. Ford needs to make an extended Expedition (rebadged as the Excursion once again, or maybe just Expedition XL, kinda like what GMC did with the Yukon), and I think they'll have much greater success. Would make for an excellent Photoshop project for right now anyway!