Well spotted! The Psychomagic for Beginners excerpt certainly takes some inspiration from that. I read that book a few years ago and really enjoyed it too.
I've already written first drafts of a couple more chapters which I'll be polishing and posting over the next few months.
So I can guarantee at least a few more installments. After that it will depend on what kind of response I get and whether I'm still enjoying the writing process.
Early in HPMOR there's a bit where Harry mentions the idea of using magic to improve his mind but it's never really taken much further.
I wanted to write about that: if you lived in a universe with magic how could you use it to improve your intelligence and rationality? If Harry and Hermione studied legilimency using the scientific method what would they discover? And also tie in some things I've been reading recently about neuroscience, psychotherapy, theories of consciousness.
If anybody fancies reading some early drafts of the next few chapters and giving me some feedback please do get in touch.