EMS has nothing to do with emoticons/smileys. EMS is an Ericsson SMS extension that Nokia has never really supported. Nokia implemented its own Smart Messaging specification, instead, and that one has adopted by virtually every phone manufacturer on the planet. EMS is primarily only a Sony Ericsson thing, and something of a mix of the Nokia Smart Messaging and MMS (almost all phone manufacturers and network operators also support MMS).
Emoticons are never transmitted as actual graphics, but text symbols ':' followed by ')' or '-' and then ')' are displayed as a smiley on the device.
Even on a phone that doesn't support the symbols, you can type the characters and on a receiving phone that does, they'll be shown.
It is true that many of the newer S40 phones do support them, but S60 never has. Not sure if the next version of S60 will; no actual devices based on it - S60 3rd Edition Feature Pack 2 - have been announced yet.