No he won't, a few reasons:

1) The TKs hate Nagash, he cursed them. They were expecting to wake up in paradise but instead they are awoke by Nagash's great spell.

2) Nagash has time and time again attempted to rule Khemri and the other great cities via war, and they TKs have forced him back time and time again. They will never bow down to him (especially Settra).

3) He will reappear in the 2005 or 2006 campaign that will be based around Khemri, and Nagash's bid to rule it again.

 

He will probably be more likely to lead a Vampire Count-esque army. The Necromancy practiced by them and the troops are what Nagash is more related with.

 

And also that would make sense as to why Manfred has no necros .... if they are all with nagash?

 

Is Nagash really returning? He got downed by one of the nastiest weapons around. I'm sure, though, if'n he does return, we are going to get a TON of complaints about underpowering. He's got to be like Teclis for Necromancy.

 

He should be more powerful, he's had centries to hone his skill in the black arts. Also he killed a whole nation and then raised them all from the dead again, and Sigmar had a tough time beating him. But while his hand/claw is still at large he's immortal.

I just hope they make a new model for him, I hated the evil clown version