I think the NWN community is still fairly active. There's probably more NWN1 online players then there are NWN2's nowadays.
NWN2 toolset is more powerful (especially in terms of external area design), and is more streamlined in some aspects (makes dialogue/scripting easier to handle at parts). I haven't touched it too much, though. From what I have, though, NWN1's is more easily accessible nevertheless, perhaps because it's just simpler to use (and less powerful subsequently).