Having a potential of 64 people talking all at once could lead to frustration and chaos. Maybe it'd be better for only squad leaders to have a separate voice chat button to chat to the whole team.
As I recall in BF2 everyone could talk to everyone else in the squad, then only the squad leader could talk to the commander. This worked very well when the system was actually used, which also meant that squad leaders follow commanders order. To be fair a lot of commanders were complete morons, but the core concept of it was very good. The bottom line is you're not going to be able to collaborate with 32 random people on a team.
Also the more people there are the bigger the map is, which also means I am further away from people. The further away I am from someone the less relevant to them "guy on top of apartments" is. Sure there are times when it is useful, "Helo jet behind you" or "Can a helo come destroy this tank for us", but most of the time what is being said on a channel with everyone would impact the majority of the people. This is why it is ideal for squads to communicate with each other, since they are (ideally) in close proximity to each other. Although I wouldn't mind seeing a 'support' channel of some sort. Either make it so every person in a vehicle is automatically joined, or if you are in a support role (basically, a vehicle) then you can opt into the channel.
Speaking of helicopters and tanks, hopefully helicopters are actually good against armored targets. In Bad Company 2 a helicopter really couldn't do much, I hope they bring it back to how it was in Desert Combat / BF2 where a helicopter coming at you was actually a big deal. Then again I'd like the flying system that Desert Combat had. Sure it was a lot harder, but you got a lot more control and it also made flying the helicopters a lot more fun in my opinion.