Yup. Nagash, Arkhan, & Morghasts all get more expensive. They also all see some changes to their warscrolls.
Morghasts are simple, they gain the OBR and Mortek keywords, letting them function in the army, take advantage of faction & subfaction rules. Very minor changes, but notably in an OBR army they provide their own death saves, so they don't need to worry about staying in range of your heroes.
Arkhan sees a number of expected 2.0 cleanups. mortal touch on the spirit attacks on unmodified sizes instead of 6+, 1's always fail to mortal on curse of years (though mortal negation abilities no longer prevents follow up rolls), bonus to unbind also applies to dispel, etc etc. No keyword changes, but if you take him in an OBR army he gains the OBR keyword. In theory this means he also gains subfaction rules, but I'm not sure that'll survive FAQ. There are some more substantive changes to his casting & healing, though. The biggest being that he gets a third cast & unbind per turn, which is a big upgrade. On the negative, he no longer knows the spells of other nearby death wizards. Instead he can cast mystic shield & arcane bolt any number of times up to his casting limit even if it's already been attempted. In an OBR army he also knows all of their faction spells, which are pretty good. In terms of healing, his heals are a flat 3 wounds instead of d3 with a reroll, and can affect either summonable units or OBR units, which in an OBR army includes himself.
Nagash sees similar changes, including flat 3 heals for summonable or OBR including himself, gains OBR keyword in OBR armies so can heal himself, benefit from subfaction rules (again, not sure that will survive faq). As with Arkhan he no longer cribs other casters' spells, can multicast shield & bolt, knows the full OBR faction spell list in OBR armies.
Not sure how or if these change will be made retroactive to LoN, but in an OBR army they both seem pretty impressive, provided the subfaction thing sticks. Nagash with a 2+ re-rollable save isn't likely to go over well with casual players.