AT&T announced new iPhone data plans earlier in the week.

Some of our readers who are existing AT&T's customers seem to be quite upset with the changes in the data plans, while some are planning to switch to the new and cheaper data plans based on their data usage.

If you still have some unanswered questions then here are some more details about AT&T's new data plans.

Let us first go through the details of the data plans announced by AT&T, which should answer some of the questions.

iPad Data Plan:

New users can purchase monthly data plans at the following rates:

• 250MB: $15 per month
• 2GB: $25 per month

The data purchased is valid only for a 30 day period which cannot be rolled over. However, users who run out of data within 30 days can purchase additional data, which shall be valid for the next 30 days.

If you're an existing iPad customer, you can choose to auto-renew the unlimited data plan indefinitely for the future.

iPhone Data Plan:

Unlike the iPad data plan, iPhone users are on postpaid contracts. The pricing plans are as follows:

• DataPlus: 200MB data limit for $15 per month
• DataPro: 2GB data limit for $25 per month
• Tethering: $20 per month (Only for DataPro 2GB plan customers)

Also, like iPad 3G existing iPhone customers can choose to retain their unlimited data plan for $30 a month. The new data plan can allow users to tweak their data plan depending on their usage requirements for a particular month. For instance, a user who has signed up for the $15 DataPlus plan may choose to temporarily migrate to the DataPro plan if they notice that they have exceeded the data cap for that month. AT&T has not clarified on whether the same flexibility will be available to subscribers who have opted for the DataPro plan as well. 

Tethering:

AT&T's new tethering option for iPhone users does not come with a contract. That would mean users can add it for as many months they want and stop using the feature anytime they choose before next month's billing cycle. 

How will the new plan affect the owners of different iPhone models?

• iPhone 2G users will not be affected since the new plan covers only 3G data.
• Existing iPhone 3G and iPhone 3GS users can choose to retain their existing unlimited data plan but they won't be able to opt for the tethering option.
• New iPhone 3G and iPhone 3GS users will have to sign up for either DataPlus or DataPro data plans starting June 7, 2010
• There is no information about iPhone 4G since Apple is yet to officially unveil the new model. But existing users will be able retain their existing unlimited data plans when they upgrade to the new iPhone.

Will the new plans increase affordability? 

Seth Bloom of AT&T thinks so. When asked whether the new plans were aimed at curbing the usage of data-hogs, Bloom said:

"It's the opposite. We're doing something [in introducing these plans] that isn't around at all. We're introducing a $15/month plan that will make smartphones available to whole new sets of consumers. It's much more affordable to them." 

Are the new plans aimed to curb data usage?

Apple is expected to launch iPhone OS 4 during WWDC next week. One of the most anticipated functionalities in the new iPhone OS is multitasking, which  will allow users to run iPhone applications like Pandora and Skype in the background, which could significantly increase the average data usage levels. 

But Bloom claims that 98% of their smartphone customers use less than 2GB of data per month. He says:

"We developed a plan that costs less than the $30 plan, where customers can use it comfortably with a fair and easy-to-predict structure if they go over their limits. I think there's a lot of value being added, consumers are getting what they need. For a vast majority of users they're getting that for less money per month."

He also goes on to add that the network issues seen on AT&T's network due to an exponential increase in data usage was not the driving force behind the change.

Are the new data plans better than a Mi-Fi alternative?

Though the new data plans appear to be expensive, it may still work out to be cheaper than unlimited MiFi data plan for a majority of users. Blogger Duncan Davidson writes:

"Running the numbers, if I had been able to use my iPhone for data tethering over the last six months — paying the $20/mo tether charge and $10 for the overage — I would have saved $230 over paying my $60/mo bill to Sprint. Factoring in the $5/mo difference in monthly price, I can expect to save $260 over the last six months of this year if I drop my Sprint card and move to tethering via my iPhone."

Will the unused data roll over? 

The unused data will not roll over for the iPad prepaid plans nor on the iPhone postpaid plans.

What are your views? Are you happy with the new data plans? If you've have any other questions, please feel free to ask them in the comments section below.

Update 1:

iPhone-iPad Tethering Not Possible Due To Software Limitations; Not A Policy Issue

Update 2:

How To Check Your iPhone Data Usage To Select The Ideal AT&T Data Plan

[via TUAW, Daring Fireball]