Co-evolution and symbotic relationships

I recently read about how domesticated foxes began to pick up the look and characteristics of dogs (as well as increased intelligence). The grew bigger, cuter eyes (obviously a desirable trait in pets) and started wagging their tails (why? i dunno.)

Plus, the latest New Scientist (19 Feb 05) speaks of co-evolution whereby different species of mammal independently evolved the complex workings of an inner-ear. (See "So Good They were Invented Twice", pp.16).

This leads me to wonder if plants would evolve to fill our aesthetic (for lack of a better word) needs as well as nutritional needs if we were to stop eating meat. Obviously, this is the view of a vegetarian -- but I'd like to think that intelligent beings would stop eating each other.