Perhaps if staff time/money was unlimited, that could happen <very sarcastic grin>.
Keep in mind some of the models you see @ Costco and/or Sam's club are unique to those retailers hence you won't find them reviewed online. They often only have very slight differences (some cosmetic/some features) from the standard models carried typically by Best Buy, etc. You would benefit from also perusing places like AVS forum to read actual user experiences with the various HDTV models.
That said, you might want to check out the 50" Panasonic G10 plasma. It's quite a deal IMNSHO.
I follow cnet daily and am constantly reading their/your reviews; and with all the new products and models coming out I understand why you can't review every new piece of hardware. One thing that surprises me though, is, on a recent trip to Sam's Club I wrote down a bunch of model numbers from TV's they were selling to compare prices. When I input the models into cnet's search box many were either not found, not available, or not reviewed. Of the 7 I wrote down I think only 1 had been reviewed, and a couple models had reviews of a different screen size. The rest were not available or not found.
I'm looking for a new HDTV over 50" and under $2000.00. It's frustrating not finding reviews of the exact sets I see in the stores. Along with Sam's I've also been looking at Best Buy.