You never know how important is it until you lose it. Average person would not know what the hell does GSM means or CDMA means.
Using Voice and Data at the same time is very important for me since I use my phone as business from time to time.
I will be surprised if verizon invests too much more money on CDMA. They will focus on LTE.
Get ready to be surprised....or perhaps the updates were cheap? To get the iPhone, I'm sure Verizon was willing to invest in the existing network. Especially if the rumors are true about exclusivity (no Sprint or T-Mobile). Although I'm not putting down any money on that rumor.
Will LTE provide simutaneous voice/data?
What bout Att future?
NO, LTE does NOT provide simultaneous voice/data....yet. It is only a data protocol as of now. The ability to support IP voice is in the works and will be released with a later update. However, no standard has been settled on for VoLTE (voice over LTE).
Yes, LTE is a GSM standard. AT&T uses GSM Already and it can do this. AT&T is also going LTE in Q2 2011. Verizon has already rolled out LTE network on 38 markets, but that's nothing compare to their CDMA coverage that covers over 280 markets. Personally, I hope Verizon doesn't dwell in CDMA and move on LTE. While I understand some people want iPhone to go to Verizon asap, Verizon is just as nervous as any other carriers about carrying iPhone because all of us can kill their network instantly. I have seen iPhone users use as much as 50GB data a month.
Once again, NO, it does not. Being that is came from the GSM Association means that may be a priority, but it doesn't make it a given on launch. Odd thought process there. WCDMA will continue to be AT&T's voice solution until VoLTE is settled...which last words were a projection of 2013 IF a standard can be agreed upon.
LTE 4G does support simultaneous voice and data usage. I'm actually contemplating switching over to them a little. I used to be an ardent AT&T supporter but they've truly oversold their network here in the San Francisco Bay area. I get speeds of about 40KBPS at my home, I literlly can't make a single five minute call without it dropping.
One last time, NO, LTE does NOT support simultaneous voice and data because it only carries data at this time. Voice will be run on WCDMA/CDMA in the meantime.
I use it all the time. As an example, I was traveling to an area that readily sells a type of spice used in Pho. My wife wanted me to purchase a certain type. I went to the store, called her on my wonderful iPhone, took pictures and emailed her the photos of various products. When I emailed her the right one, she confirmed it over the phone. I am always looking up crap on my Dropbox account as I am talking with someone (business).
Star Anise?

I used to have to eat Pho at least once a week or I was a very unhappy man. Lost my craving though. Seems it's harder to find good Pho these days. Tons of places opened, but quality went down.
Edit:
http://www.youtube.com/watch?v=N4Kjq4sGO44
(warning...some ppl find offensive...I find it funny as he##)