Googling doesn’t reveal anything even remotely promising, so I’m going to say that it’s not possible.
I did find text-overflow: -o-ellipsis-lastline
, but it only works in Opera: http://people.opera.com/dstorey/text/text-overflow.html (mirror: http://jsbin.com/exugux/)
There’s also a similar WebKit-only solution: http://dropshado.ws/post/1015351370/webkit-line-clamp