With all of my previous iPhones / iPods, I found myself using the docks frequently and usually kept a few at home, one at work an even one in the car. With the iPad, I prefer a stand because I find myself wanting to switch between portrait and landscape more frequently. With the improved battery life, I don't feel the need to keep it plugged in all the time. When it does need charging, I can still keep it in my stand with the charging cable plugged in on the side or top (iPad sitting in the stand "upside down"). I guess the ability to turn the iPad upside down and making the 30-pin connector more accessible is one of the main reasons that I find the dock less necessary. Oh, and then final reason I don't want the Apple dock is that I have a TPU case that I love but would need to be removed to use the dock.
In short, my recommendation is to hold off on getting a dock until you know how you are going to use the iPad.