I doubt there won't be, seeing that this is EA and Will Wright we're talking about. Just look at the Sims. Now why would this be so much different?
First off, WW does not like expansion packs, it was only after they were bought out by EA that each game had a bazillion EPs; second off, will said he was going to expand spore broadly, instead of deeply, meaning that instead of releasing EPs, he would release smaller games that were like portions of spore for handheld games, etc. and seeing as lots of different games would make more money that lots of EPs, I
think EA will go for this. But then again, when the head of EA is kneeling down infront of Lucifer, he might decide that a 2D plane covers more space than a 1D line.