I bit the bullet and ordered a copy of Space Hulk.

However, since it's my understanding that they are starting to arrive on people's doorsteps, I have a question:

What are the differences in the rules from the old edition to the new edition?

...this needn't be an exhaustive listing, but some of the key points - if any. I'm concerned that they might have spent all their time sculpting and very little revising the rules.

Can anyone who's seen both editions help out?