4G is definitely coming, and it is going to be huge, considering it is being backed by 3 of the world's largest providers. As for the speeds, I know that it supports 10 - 12 Mbps, so this information about 40 Mbps sounds interesting. Also, 4G / LTE would provide more coverage than the existing CDMA technology does, allowing for even larger cell sites, in addition to providing better signal quality.
CDMA, GSM and 3G are not the same thing, nor is 4G/LTE. It seems like kbps and kBps, some people are mixing their terminologies. 3G describes a family of standards which covers GSM/EDGE/UTMS, CDMA and more recently WiMax and DECT. The two basic technologies (CDMA/GSM) are not compatible, and even require different model phones (If you have a CDMA phone, don't hope to travel to many places with it - thats why I have a phone for Japan and Korea, and a phone for the rest of the world).
The networks that I'm aware of in India using CDMA are Reliance and
Tata (and therefore, potentially Virgin Mobile also), although Reliance now has a GSM network also. The first 3G capable network was introduced by NTT DoCoMo in 2001, branded as "FOMA" (I was in Japan during the launch, which shows just how far behind India is right now).
Essentially, the purpose of the 3G label is to define the data rate at which the network operates. 3G (3GPP/LTE) currently supports up to 21Mbits, and they're testing stuff which will do 42 Mbits. 3GPP/LTE-Advanced are considered to be "pre-4G", since it doesn't quite hit the magical 1Gbit-capable mark - it is these things that are being deployed in the next couple of years, because as mentioned in previous posts, 4G still isn't quite there yet.
4G/Mobile WiMax etc is supposed to deliver up to 100Mbits while moving, but as mentioned, real-world rates are closer to 40-ish. When stationary, they might be a bit higher, but as I understand it, not by much.
For the next few years, what is marketed as "4G" by the likes of Verizon, Sprint and Vodafone is actually simply 3GPP "redefined" - as 3GPP is being built to reach most of the same goals effectively as 4G set out to do, and is likely to actually become the standard later on. Currently, they're up to about 320Mbits. We're building our network to handle at least 21Mbits for now, since this is the fastest commercially available offering at the moment.
DoCoMo is doing some very interesting stuff with MC-CDMA to actually achieve the speeds 4G is after, but it's all very prototypy right now... I wouldn't be surprised, however, if they're the first Gbit capable (effectively, therefore, 4G) mobile network in the world. If we're lucky, I would like for my company to be the first 4G network (or at least, 100+Mbit capable mobile network) in India.
Qualcomm (the primary promotor of CDMA) will be essentially dropping 3GPP2 and joining forces with the 3GPP camp to continue and enhance its development.
As an aside, because of some changes in how we'll be delivering things, we've now got plans ranging from:
[*]512kbits to 21Mbits for mobile (3G v1 capable phones will get 384kbits only, 3G v2 will get up to about 2.5Mbits and the latest models should get 7.2Mbits. For higher speeds, we have a USB-stick).
[*]1mbit to 200Mbit for fixed-line (glorified ethernet - no cable modems or any of that rubbish unless we absolutely cannot avoid it)
[*]1Mbit to 42Mbit for fixed-wireless (which, unlike some other ISPs, is not shared between every WiMax user in the building)
[/list]Prices have gone down a bit - we're not releasing them just yet - but we're almost breaching the under Rs1,000/mbit/month goal.