I forget you haven't played before, yeah you should be exited. A lot of people have complained about Sims 3 and what they're missing, I think they forget how much of the fun was added with the EP's. It can be new neighborhoods or new careers or entirely new gameplay elements, for example gardening and fishing were added in EP's. Or new sims; your sim could become a werewolf or be resurrected as a zombie.
Here's a list of the EP's for Sims 2 to give you an idea of what we might expect.
http://en.wikipedia.org/wiki/The_Sims_2#Expansion_packsMy favorite was Seasons which made the seasons change. For example in the fall the leaves fell off the trees and you could rake them up and compost them to use as fertilizer in your garden and in winter sometimes it snowed and your sims could have snowball fights and build snowmen. Oh and the garden plants went dormant in winter so no gardening and the ponds for fishing froze over. That made the everyday life of your sims change with the seasons.
I'm hoping for new causes of death. The old expansions added them in gradually, eventually I think there were quadruple the ways to die in the Sims 2.
I don't remember that, I think I must have missed most of those. Maybe that should be a section of the guide, "How to Kill a Sim".