I'm just imagining the current iteration of the sims, with even a 20x20 field full of harvestable, say, carrots. It would just be endless gardening. By the time the sim maintains the last plant, the first one will certainly have already started to need some sort of attention...
So I'm thinking this farming pack would need its own irrigation system (which, didn't we get something similar in Seasons? At least a sprinkler? I don't really garden in the sims--not sure, but even if a huge sprinkler system were part of seasons, they would need a new one for TS4 Untitled Farming Pack) and we may also need a roomba-esque harvester machine... (because I couldn't see EA providing a driveable combine to harvest crops). But even planting--in real life, my dad would plant a few fields of corn or soybeans, and it would take him hours. I couldn't imagine traveling to an empty field lot and watching a sim circle the lot in a tractor for over 12 hours.
I want TS4 to feel real and offer well-rounded simulation, but I also worry about multiple packs feeling repetitive. So for me, farming would definitely have to focus more one farm animals rather than plants... Unless it's about making products OUT of plants (like nectar--and pickling/jamming, good suggestion).