On February 13th, AT&T will formally launch their AT&T Mobile Hotspot application in conjunction with the release of the HTC Inspire 4G. Now there are rumors that it may not be the only AT&T smartphone to offer hotspot capability on that date. The New York Times initially revealed, as part of a review of the Verizon iPhone, that the release of iOS 4.3, which will give AT&T iPhone 4 devices hotspot capability, may be coming the same day. That would make the release only a few days after Verizon’s launch of their hotspot capable iPhone 4 on February 11th. The New York Times review has since been updated to simply say “AT&T says its iPhone will get it soon.”The launch of the HTC Inspire 4G also marks the day that AT&T will be updating their smartphone tethering plans to put them more in line with the AT&T Mobile Hotspot offer. HTC Inspire 4G users will receive a data cap of 4GB when they bundle the hotspot capability with their AT&T Data Pro plan for $45 a month. In contrast, AT&T’s current smartphone tethering plan costs subscribers an extra $20 a month in addition to the $25 monthly cost of their AT&T Data Pro plan, but the plan doesn’t include any increase in a subscriber’s 2GB monthly data cap.As early as February 13th, current tethering plan subscribers will receive an additional 2GB a month which will raise a subscriber’s total monthly data cap to 4GB at no additional cost. Subscribers going over the 4GB monthly allowance will pay $10 per gigabyte. AT&T will send customers a text message once the additional 2GB has been added to their account.Read more at AT&T and AppleInsider.Brian’s OpinionYou can bet AT&T is quickly shuffling what it needs to in order to keep as many subscribers as possible when Verizon Wireless begins offering the iPhone 4 on February 10th. AT&T has previously been able to wrap itself in the security blanket of an exclusive agreement with Apple, but all that goes away in a little over a week. That’s what makes the release of iOS 4.3, only days after the launch of the Verizon iPhone, so believable.If the Verizon iPhone has hotspot capability you can bet AT&T wants their iPhone users to have it as well. The carrier is also bending over backwards to offer the capability on their line of Android phones, beginning with the HTC Inspire 4G, and to ensure customers who tether their smartphones don’t feel ripped off by not being included in the additional 2GB a month HTC Inspire 4G owners are getting with the AT&T Hotspot app. These moves by AT&T is yet another example why competition is good for consumers and why exclusive agreements only benefit hardware manufacturers and carriers.The battle between AT&T and Verizon Wireless will be a bloody one for the rest of the year as each carrier battles over the retention and addition of subscribers, especially when it comes to iPhone users. The battle will be a prolonged one because many AT&T customers, especially recent iPhone 4 purchasers, are still going to be within their 2-year agreement with AT&T. Though it may not be a flood AT&T has to deal with, they will need to watch for subscribers trickling away to Verizon Wireless.