Summoning is indeed dead in the water, which I am personally happy with as less summoning in AoS is a good thing. Sacrificing 2 spell casts to get 1d3 points on a slann seem very inefficient, bringing a 260 pts 3 cast wizard, just to not cast. d3 points will on average require 3 rounds to bring home 6 points to summon a 10 man skink unit... Is that really worth the 6 spells you missed out on? I don't think so at all.
I can see both starborn and coalesced being good though. Starborn lists with teleporting blobs of skinks or salamander units will be really good, supported by casters who can become quite potent, with the staff buff you can choose now, and Slanns getting +1 cast by default and astroliths giving +1, you can get +3 to cast easily. I can see Kroak on a balewind being an absolute terror, or maybe even garrison him, the astrolith and some saurus guard in the pyramid...
Coalesced will be my main choice though, I am not too fond of skink hordes, and coalesced lends itself to saurus and/or monsters. My first go will be with thunderlizards. While the skink chief on stegadon is really good, I still love the carnosaur models so much, and they can be potent as well now. With the command trait, the base +1 jawz attack and possibly the +1 attacks to a hero choice, you can get an oldblood on carnosaur to be quite dangerous, and with 14 wounds and scaly skin, they can be quite efficient, with 6 bites with 5 dmg, 5 claws with 2 dmg and the oldblood himself with 4 attacks with dmg 3. That is very nice for a 250 pts model monster indeed!
I don't think saurus guard will see much play outside of starborn Slann babysitting, why take a saurus guard over a saurus knight? Saurus knights as coalesced get 7 attacks total, and will do a lot more average damage, they also got way more move, the same save, same wounds and bravery. If saurus had 2" on the polearms maybe that would help them out some, but as is, they only got 1" so I think saurus knights win every time.