PTR Report:
The elemental changes hurt. Except that if things stay the way they are, this is actually a massive buff, even with the huge coefficient loss... the problem is that the way the changes were implemented look buggy, but if they stay the same it's huge.
1) Lightning Overload only reduces the _base_ damage of the spell when it procs.
For a quick demonstration of why this is significant, if you have +1000 DMG and lob off a Lightning Bolt in 2.2, it hits for 603 (base) + 857 (+DMG coefficient of .857) = 1460 before things like Convection or Stormstrike or whatever are factored in. In 2.3, this drops to 603 + 714 (+DMG coefficent of 714) = 1317, which hurts.
Now, Lightning Overload. The talent has changed to quadruple the chance to proc, but the procs are supposed to do half damage... so a LO proc would do (603 + 714) / 2 = 658.5 damage. Except that's not how it's working. LO is only reducing the _base_ damage, so you actually get a LO proc at (603) / 2 + 714 = 1015.5 damage dealt.
This is huge. The more +DMG you have the more effective it'll be, but it means that LO is going to be doing enormous amounts of damage... unless this is a bug and is fixed, which is possible.
2) Lightning Overload procs off itself.
Not much more to say on this one, actually. Much like Sword Specialization and Windfury Totem for Rogues/Warriors, Lightning Overload can proc off itself... thus netting you 3 Lightning Bolts 4% of the time, and 4 Lightning Bolts .8% of the time. It's a fairly significant boost in damage, and a huge boost in potential burst damage... for no threat in PvE, and insta-gib potential in PvP.