From what Enhancement pass has shown us Sorcs and Wizards lose their Repair Manipulation enhancements and having them replaced by the repair skill, now for reference I maxed out concentration on my casters and I got it between 50 and 60 so that means maxing out repair will be about the same, how is 60 spell power as good as 100 spell power?
Casters lose their Deadly enhancements (ie. Deadly Acid) and instead gain a skill that boosts their elemental spell power, this skill might help wizards as it is INT based and wizards do have the skill points to spend on it, but sorcs are out of luck because they are not INT based and even if they put some points in it they can only expect about 40 or so from it, for reference lets use Polar Ray (CL:20) the average is 5 x 20 which is 100 base damage assuming 200 spell power it will do 300 damage and on critical it can do 2.65x that damage (Deadly Ice V + Superior Ice Lore) that's 795 damage on the other hand with this new system it will do 340 x 1.5 which is 510 in fact in order for this new system to dps like the old one the skill would have to be 200+.
Finally, I've heard rumors, and it would be great if someone can confirm or deny these, that they are nerfing shriadi making it so that its 7% chance per spell cast not per missile, which means now it will take forever to get double rainbow or nerve venom to proc. The whole reason people went shriadi is because DI's DC is far too low to be viable on EE (at least for first life Sorcs) now the devs, it looks like, want to force people to adopt an inefficient system for dealing with EE. Not to mention with the level cap reise to 28 we're going to start seeing new monsters with higher saves and HP all the while keeping our same old junk DC (maybe augmented by 2 or 3 points which still doesn't mean much) and even worse DPS.
So maybe with all these things in mind it would just be smart to TR our casters now into something that would be useful after the update, such as melees and healbots.