I have just finished the website for my brother restaurant The Black Rat. http://theblackrat.co.uk
It was interested to make a site on wordpress.com using their controls. You do not get much you can customise but I got the domain to map and email set up for them on google apps. So seems to be a quick way of getting people an online presence while they work out what they want.
It would be nice if you could add more code to the pages as it stripped out the google map i added. So that seems to be where worldpress.org versions of the sites come in. Also you can not add your own google analytics as they use it so you get very basic stats. Also I am not sure if page rank is affected by being part of a hosted site. we will see.