If you stop at the other resorts, and ask, it may be possible to see a room but I wouldn't count on it.
Oh, I think you'd be surprised. They are normally pretty accommodating.
Just to elaborate, the sales center is located at Saratoga Springs. At SSR they have model rooms for both SSR and AKV, the two resorts actively being marketed now.
There is also a small walk-in sales center on the BoardWalk. It's down near the Big River Grill. You'll have to make your way over to the BW on your own. There will be a Disney CM on hand simply to look over your shoulder as you examine the room. This CM isn't a salesperson--he/she is the same level as those that staff the dozens of
DVC booths at the resorts and theme parks. It's basically a self-tour opportunity. If you have any in-depth questions about DVC, you'll have to arrange a formal tour at the SSR center.
For the other resorts you can stop by the front desk and inquire about seeing a room. If they have a clean, vacant room available and can spare a CM, they will escort you up to the room for a quick look around. Again, no transportation provided and the ability to do this is subject to a number of factors.
The room layout at SSR, BWV, BCV and VWL is virtually identical. The major difference is simply the style of furnishings. By visiting the models at SSR and then viewing photos of the different resort styles, you can get a pretty good feel for each property without seeing them first-hand.