AT&T has come out with several new plans, and the much-awaited tethering plan will also be on the offer soon enough, exclusively dedicated to the iPhone users.  TetherBerry was a very common app on Blackberry and tethering functionality became extremely popular within few weeks of launch of tetherberry in the market. And, now finally after a wait of almost a year or so, iPhone users will finally be able to make full use of the tethering functionality with the special tethering plan.

The bad news is that those who’ve been enjoying the unlimited data downloads will end up paying considerably more, as the company has set a 2GB cap on the data plan, and AT&T has now devised a 2-tier strategy.

iPhone tethering will be possible after iPhone OS 4.0 upgrade, but we don’t know as to when the new plans will come into effect precisely. And, the new smartphone plans will be very much applicable to the iPhone as well as iPad plans, as all the users will now have the 2GB/month download cap. Indeed, this clearly means that the so-called “amazing” pricing on the iPad will no more be impressive, and just after one month of iPad 3G availability, customers will have to face some serious disappointment!

Sure thing, this will also bring some relief to the low-end users, who don’t really download a lot of stuff, and are happy enough with 200-500MB download limit. But, on the contrary, this will make the existing data plan hell a lot costlier for those who’ve become addicts of unlimited download freedom.

Coming to the tiered pricing model, the lower-end data plan will feature the DataPlus plan priced at just $15/month that will allow 200MB download limit, and the customers will be able to add another 200MB to their download limits by paying $15 extra.

Similarly, you’ll get 2GB cap for $25/month, and you’ll be charged $10 extra for subsequent 1GB usage. This simply means if you consume 5.5GB then you’ll end up paying  $25 + $40 = $65, which isn’t too reasonable by any means.

But, the biggest losers in all this drama will be the Apple iPad 3G+Wifi users who were promised unlimited usage for just $30 a month, as opposed to $25/month for just 2GB! AT&T and Apple claim that majority of the users are happy with 2GB limit, but those who’ve been enjoying unlimited downloads will be utterly disgusted with such a nightmare just after one month of iPad 3G launch!

Taking a look at the low-end DataPlus tier plan, which has 200MB cap, the price per gigabyte works out to be somewhere around $76.80. But, sadly, these users will get only 200MB for extra $15, unlike the DataPro plan users who can avail additional 1GB for just $10 extra. And, in contrast to the DataPlus, the Data Pro plan will cost just about $12.50 per gigabyte, with good scope for additional usage at a reasonable price of $10 per gigabyte.

On the other hand, Verizon’s plans have $29.99 cap for smartphone users at a monthly price of $29.99, while the per gigabyte price works out to be $6.