I don't think any product line in any industry can stand still for very long, for various reasons. Some of the changes are good and some are not so good.
I would probably enjoy a new 620 and who knows, someday I may buy one. But it would never take the place of an earlier model 13, 19, 65, or 66. There is just a quality, a nature, a look and feel of the Smiths made in earlier years which has an allure head and shoulders above all the Starwars inspired, post-post-modern age wheelguns S&W is making today, those wearing atomic symbols and locks and all the rest of it. I understand that S&W needs to go there for various reasons and we'll probably never see another S&W without a built-in lock (dang it!!!), but like another poster said, it would be nice if S&W wakes up and realizes that continuing to build some of the classic designs would please a LOT of people. Perhaps, though, most of us that are drawn to the earlier versions of Smiths will fade away and the younger generations will take to the new-fangled Smiths with joy. In the meantime, I continue to seek out and enjoy beautiful Smiths of a slightly earlier time. I think they will hold value or appreciate much more than anything coming out of the S&W factory today and they also happen to bring me a lot more owner satisfaction as I enjoy looking at, handling, and shooting them.
There is one use I personally might find for a brand new Smith... that of a "beater" gun... a gun you don't mind throwing in the glovebox or under the seat of your car, one which you know you can rely on but don't have to be concerned for as far as keeping in beautiful condition. Brand new Smiths are more "disposable" in that way, you can easily replace them if they get messed up... a beautiful older Smith is not so easy to replace.
I feel the same way about 1911's. That's why most of the 1911's I've bought over the last few years have been Colts. And most of the rifles I've bought have been Winchester and Marlin lever rifles. Guess that makes a real statement about where my firearms preferences lie. Not to be totally type-cast though, I thrive on and love new Macintosh computers, new cars, DVD players, new TV's and stereos, new digital cameras, etc.