i'm not so sure about the 1-3%. i guess 50 % of all mac sales are notebooks. and i guess half of that are desktop replacements. so maybe 25% of all users could use a docking port.
I still don't think so. If those computers are desktop replacements, how many of them are using an external monitor? Probably less than 1/3 of those that bought a laptop for that manner. And even then, they most likely have all the necessary things to expand their capabilities without a dock.