As Gary Kim points out, AT&T will soon be revamping its data rates and plans for iPad users. Currently the plan is $30 for an unlimited amount of data per month. Going forwards, DataPlus will provide 200 MB of data for $15 per month (additional 200 MB chunks of data also cost $15), and DataPro, which provides 2 GBytes of data for $25 per month, with every additional GByte costing $10.

Here is more from Kim:

If customers on the DataPlus plan exceed 200 MBytes in a monthly billing cycle, they will receive an additional 200 MB of data usage for $15 for use in the cycle. Currently, 65 percent of AT&T smartphone customers use less than 200 MBytes of data per month on average, says AT&T.

If customers on the DataPro plan exceed 2 GBytes during a billing cycle, they will receive an additional 1 GB of data for $10 for use in the cycle. Currently, 98 percent of AT&T smartphone customers use less than 2 GB of data a month on average, AT&T says.

Furthermore, smartphone customers can enable tethering for an additional $20 per month, but only if they use the DataPro plan.

Existing iPad customers, who already have the $29.99 unlimited monthly plan can choose to keep it, or switch to the DataPro plan.

From a user perspective the decision to keep the unlimited plan shouldn’t be taken lightly – especially if you are a fan of streaming radio or Skype. With multitasking coming on the iPad, it will be able to use the device as a high quality sound system. And videoconferencing on Skype over the 3G network will certainly eat lots of bandwidth.

Larry Dignan points out that some will mourn the passing of the unlimited plan but on the bright side, most consumers will pay less based on past data usage and there will be a welcoming simplification of plans. Perhaps he is right – and my usage behavior on the iPad has shown me that I constantly look for WiFi networks as using them saves battery over 3G and quite often WiFi can be faster.

More potentially good news is tethering will arrive on the iPhone and any other smartphone for $20 a month on top of a DataPro plan. This equates to $45/month for a 2 GB plan with tethering.

AT&T has hinted about changing its data plans for a while and you can’t fault the company for looking ways to make the maximum return on its investment. This is especially the case in the world of broadband where generally a handful of users hog up inordinate amounts of bandwidth.

As consumers we want to pay the least we can and get the most for our investment. As Americans we also like freedom – the freed to have things like unlimited refills on our sodas and of course unlimited wireless broadband for a fixed price. Will AT&T be starting a trend here which all carriers in the US mirror? Many wireless carriers already have caps around 5GB per month on wireless data use so perhaps this news isn’t so earth-shattering.

But it could signal a slow and steady shift to getting consumers used to paying for the data they use. And this can be great news for wireless infrastructure companies as well as companies providing backhaul to towers. Ceragon, DragonWave, Aviat Networks Adva Optical Networking and Allied Fiber are just some of the companies who will likely see more business as a result.

Steve Jobs explaining AT&T’s increasing need for wireless backhaul