hers what i think:
First a big monster or two.
what comes to mind is thunder lizard and Coatl.
new special choise something like tank just a turtle.
Kroxigors having base T5 and S5 giving them GW or no weapon (counts as two hand weapons), posibly frenzy, than meiby i would agry on the price tag they have.
Saurus definetly geting more I, no A decrease that would be stupid. IF I isnt upgraded than give an option for GW.
Skinks, T3, or lower the points drasticaly (for cohorts).
RARE:
salamanders, good as they are. people should stop whining. Meiby to satisfy the whiners make 1-2 in a pack (i personaly almost never take 3).
Razordons, think something interesting.
Carnosaur hunting pack with saurus handlers, if theres no option for these than make razordons CC maniacs. Frenzy, hatred (someone is in theyre teritory, ragh!!!).
Stegadons, make howdah optional choise not included in the price. A steg should imho cost about 200 nowadays.
Make carnosaur more resilent for shooting. Prise is good as it is imo, and make hunting pack each carno 210 points.
lower COC price atleast like DE COC.
Our own lore, this is a must, the oldest rase should have theyre own lore.
ideas for lores, few (1-3) old one lores tepok sotek chotec. or ice magic, geaomantic magic for moving terrain or building terrains on field. Force magic for making protection bubles or shock releases. or some lore with rain of fire frogs, seen in page63.
make skink prests to be able to take light and beast as well that would be enough.
some rule same manes as TK came from below only that lizardmen could come from forests.
A new rase specifik speacial rule that army is so adapt in forets that theyre invisible in forests, so warmachines cant target them.
more core units. my personal best is exploding toads

they jump on enemy unit, scaters in your wanted direction d6 small template, the frog is dead but it inflicts something.
thats all i guess

well theres alot of ideas but i doubt that GW will make something good, the main purpose i guess will be to nerf magic sadly.... but if they do that than this army will lost abig part of theyre fluff, i gues they should be magic dependent and magic should be very strong.