Hey there!
I've been playing with MoI3d for some days now, and I have to say, it's really nice.
It's so simple and comfortable, that it's the first 3d modelling app that I can't keep myself away from (normally I'm kind of scared away by new software, both NURBS based and Sub-D/poly tools).
There are some limitations though.

I would like to be able to select segments between points, so I can "open" curves, by deleting these segments.

Also seamless converting points between "Corner points" "Control points" and "Through points" (plus a few extra maybe? Like PowerNURBS for 3ds max www.npowersoftware.com)

And maybe more control over the ability to change objects based on curves, like revolve.
There is not much control over the connection between the curve and the object. You don't know when the "tie" between the curve and the object is broken, and it's a connection you can not control, so maybe moving the curve will change the revolved object, maybe it won't.

Also, when drawing a curve, it would be nice to "undo" where a point is placed, so you can reposition it while creating.

And one final wish, that would be REALLY nice: adding an image as viewport background, so you can trace curves or shapes from sketches. I have a sketch of a bowl I'd like to make, but I can't trace it, making MoI useless for the job...

Anyway...
Just some thoughts :)