Many of the nerfs are directly targeted at the combat-free farming that was epidemic in Inferno.
I approve wholeheartedly - having a hack and slash where your best bet is to never hack or slash anything is madness.
If I understand correctly, destructible items means just that - destructible items. So, if you click on an item was a missile attack and you shot it, it's destructible. Things like corpses, ect, where you'd actually have to walk over to them - are not affected.
The IAS nerfs - we knew that IAS was crazy overpowered, and it needed to be nerfed. Mathematically, I'm pretty sure as of now your best bet for DPS will be a mix of crit chance, crit damage, IAS and primary stat. That actually should work out well for everybody in the end. Someone who already got lots of CHC/CHD will be better served by adding in some IAS, and vice versa - which means everybody's spreading around it in multiple slots, spreading out demand.
The repair changes by themselves would've been horrible - but with the drop changes, they're less so. Since it's now actually possible to gear up for inferno act 1&2 in Hell 3/4, and for Inferno 2+ in Inferno 1, it's a way to keep players from death rushing in acts higher then they can actually handle.
You can now actually get gear better then would drop in pre-patch Inf 1 in Hell 3. Makes it quite reasonably possible to heavily gear up in late hell until you're properly kitted out for inferno. The repair penalties give you a very good reason to do so, instead of rushing as deep into Inferno as you can for the higher drop %.
Haven't had a chance to actually play, and won't til tonight, but it really looks to me like a huge improvement.