Interesting to note some of those complaining about Live View in this thread aren't even using the K20D...
Admittedly LV may or may not be for everyone but if one doesn't even own or have a K20D, it is kinda hard to lend any credence to any comments of the supposed failings of LV on the K20D.
Personally I was initially wary of the benefits of LV but after using it firsthand, I have found it to be quite useful in certain photo taking situations. So I would say Pentax did the right thing incorporating it on the K20D.