the dark angel deathwing rules will also be a much better 'codex' version to boot;
- all your termie squads are 5-man!
- you can use company vets and/or regular tactical squads to 'count as' regular veteran squads.
- dreads have more options again which go back to how they were in the original 3rd edition space marine 'dex.
- rhinos, razorbacks & land raiders fill out all the transport options.
as for belial, just re-name him obviously. he does have a few options - shame he can't take a combi-weapon though.
you can still add in a chappy as well with your 2nd HQ choice... plus you can turn 1 termie squad into a command squad w/standard bearer & apothecary!
cheers!