The Mindstorms that I remember (~2004, on the RCX 2.0) was nothing like LabVIEW; I haven't played with Scratch, but from what people have shown me of it, it is very similar to how I remember Mindstorms.
I've taught students both mindstorms NXT and Scratch, and they're quite different. Scratch is basically procedural programming with blocks instead of text. Mindstorms has some of that, but variables/data connections are really different and wierd to get your head around if you're already a programmer. I've not used labview so can't compare to that.