As far as I know, Ian is the sole person working on SQLObject and FormEncode.
Actually, I've been lapsing on SQLObject work, but thankfully Oleg has been doing a good job maintaining it, and there's a group of people answering questions about it and submitting patches. So it's working out fine. There's been other significant contributions to FormEncode, and I'm hoping by keeping its scope very limited and clearly defined that it will also be able to exist on its own at some point, maybe even reach "maturity". And while Paste represents a particular vision of mine, I hope to bring other developers and visions into it; I know it's not easy getting an open source project to the point where it really is a collaborative project, but it's possible and something I think about quite a bit as I develop these things.