Love the addition of toddlers (finally!), and they've never been this in-depth. (or adorable!) Also the Vampires game pack - I haven't been this excited for any kind of pack since TS3: Supernatural.
Also Pets will be the next expansion pack. (Not confirmed, but code from the newest patch leaked and it has several Cat, Dog, Small Dog and Horse code strings) That basically confirms that it is the next expansion, since two months ago, some code leaked that revealed the possibility of a Vampire game pack. Overall, this look like it'll be a good year for TS4.