Rails3.1 templates & engines

with the new version coming soon, I wonder what would be the best
direction to test in design a multi-sites application, in which
controllers & models would be the same but the views would be
different..

I mean having 1 site domain ''mywebsite.com'' but 3 sub-sites :

johndoe.mywebsite.com
albert-einstein.mywebsite.com
eleanor_rigby.mywebsite.com

each of it rendering html differently ( layout & CSS) as originally
selected by the site admin ( john doe, albert einstein, eleanor
rigby)
does the Rails3.1 engines/templates capability can help ?

vs the standard way of creating n subdomains, n apps and n
databases....

your feedback & guidelines will be welcome