This is interesting.
Wyatt Cheng made a huge post over at reddit recently, and had parts of it copied over to the bnet forums here:
http://us.battle.net/d3/en/forum/topic/7592581161?page=18#348
Important points -
Monster density will not be altered anywhere.
OWE will not be changed.
Rubies will not directly increase IAS.
The general Radius buff is very small (sounds like less than 5 yards).
Stacks "should" carry over between Acts.
And lastly, Wyatt Cheng seems to consider the reddit subcommunity a place to post this kind of information first, rather than bnet itself.
I'm hardly an expert on Barb but the general point of advice I can give is to make AR among your last priorities in gearing as opposed to your first. Unlike how it was in May, D3 is much more suited to high offense than high defense. Get some socketed weapons with Life Steal, an LS belt, prioritize Strength and CC/CHD (and IAS if you can afford it) above Vit and AR, and play on low enough Monster Power that you are speedily killing everything on the screen. I share my Nat's ring and Inna's pants among my 3 60s, and my barb is at 102K DPS and 31K life now.