Access to new items a season early. The items are released to the general player base at the end of the season.
The patch itself is too big to summarize succinctly. I'd probably forget something myself if I tried. I suggest going to diablofans and reading up on it. They've broken it down nicely into sections that may or may not concern you.
I know LoH got a huge buff this patch. I seem to remember they were going to change how LoH coefficients on abilities worked too. But I can't find that anywhere in the patch notes. Was this scrapped?
Nevermind, i r dum. LoH applied in full once per attack. Certainly makes choosing between some abilities much easier.
I wonder why the boosted LoH, regen, life per resource, but not life per kill.