custom maps? this game has nothing but random generated maps, both galaxy and planetary.. never heard of a "custom map"
if you mean custom content.. i just went to sporepedia and jumped to page 100, with 20 items per page, that makes 2000 creations (i don't know how much further back i could go) all made today, and it's only 9:30am. that's not to bad really.
if you meant mods like platinum spore and better spore... then no, there is unfortunately pretty much nothing on that front lately. --- i tried being serious once, in 1989.. didn't particularly care for it.. so don't expect it to happen again.