That feature has been around for a while, you can actually change the length of the pause (and a couple related things) under Phone Options -> Smart Dialing. Including what is the number for your own corporate expensions (so you could store a number that is JUST the extension) and how long to wait before dialing the extension (internally and externally).

Of course if you think that is cool, if you are under BES just type someone's name (same format as your corporate outlook directory stores it in) and select LOOKUP and watch the BB retrieve all the contact info from the company's Exchange server. :-)