The last time I looked for an 88-key non-weighted MIDI controler, I couldn't find anyone who was still selling them.
This is not something I want to get to immediately, but I am finding it diffcult to play after a wrist injury, and I've never been entirely happy with my weighted MIDI keyboard. It's reasonably close to the feel of a piano - but it seems like it would be more natural using an unweighted keyboard for some types of virtual instruments (organs, wind instruments, etc.) I should say here that I always end up adjusting the volume and controler FX after recording, rather than doing it live. So, not capturing the dynamics or aftertouch isn't a big issue for me.