Interesting. At least half of the nice looking (in the pictures) trucks I find here are 4x4 and I don't want a 4x4. I already have an Escalade for me and I was wanting a Tahoe for my wife to replace her SRX (we both like the look of the Tahoe) but the deal was that if I get a Tahoe its getting a 6.0L swap (mainly to delete the AFM and any oil consumption that's already there and because a 6.0L from a 2500 is half the cost of the 6.2L used) but by the time I buy a Tahoe and do that I could just buy a Denali or Escalade from the start and not have to do an engine swap and get the better leather, better sound deadening, etc. I do think a Tahoe with the big engine is cool and maybe if I already owned the Tahoe for a few years the value of swapping would be different.
Most of the 6.2 Tahoes are 4x4s but there is a 2WD currently for sale, maybe two. I also located two 2008s that were 2WD also.
GMC Denalis and the Escalade also came in 2WD variety, not as rare, but still have to look for them.
My own preference is to have the 4x4 capability and besides increased maintenance costs and a slight tow weight penalty, it does not appreciably reduce fuel economy numbers.
Don't NEED it but is nice to know it's there, especially for when my wife drives it. They're leaving for church in a few minutes and the roads are soaked and it's still raining, they're going to take the truck even if she'll kill the mileage and drain the tank! (My ankle/achilles is no good right now for walking)