Fine, three things.
Google Now IMO is more "Life Aware" (package tracking, sports scores, traffic conditions, weather, live flight status thats automatically setup, events nearby, nearby public alerts, public transit times, location based reminders, just to name a few)
Today is more, well, "Today Aware" (Forecast, how long until you're home, Today's upcoming appts(even though the calendar is right underneath)).
If you'd like to compare a Yugo to a Porsche because they both have wheels and seats then I guess thats fine too.
EDIT: Google Now is completely setup using your Gmail Account. Package Tracking, Hotel Reservations, Flight Status, etc cards are populated using confirmation emails to your gmail account. In case anyone wondered how that worked.