One of the best qualities of SICP was its use of mathematical examples/exercises. But since it is a soft. eng. book and not a comp. sci. book, most of their intended audience probably were not mathematically mature enough to forge through it.

It'd be potentially beneficial for soft. engineers, to convey the core concepts through less sophisticated examples and exercising.

So a new edition -- still in scheme! -- is warranted IMO, though I'd never read but as a teaching tool it could be wonderful.